Polymers For Use In Electronic Devices

ABSTRACT

In Formula II: R is H, halogen, cyano, hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl, silyl, hydrocarbon aryl, substituted hydrocarbon aryl, heteroaryl, substituted heteroaryl, ally, or vinyl; R2 is halogen, cyano, hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl, silyl, hydrocarbon aryl, substituted hydrocarbon aryl, heteroaryl, substituted heteroaryl, ally, or vinyl; R3 and R4 are the same or different and are alkyl, fluoroalkyl, or silyl; x and y are the same or different and are an integer from 0-2; and * indicates a point of attachment.

BACKGROUND INFORMATION Field of the Disclosure

The present disclosure relates to novel polymeric compounds. Thedisclosure further relates to methods for preparing such polymericcompounds and electronic devices having at least one layer comprisingthese materials.

Description of the Related Art

Materials for use in electronics applications often have strictrequirements in terms of their structural, optical, thermal, electronic,and other properties. As the number of commercial electronicsapplications continues to increase, the breadth and specificity ofrequisite properties demand the innovation of materials with new and/orimproved properties. Polyimides represent a class of polymeric compoundsthat has been widely used in a variety of electronics applications. Theycan serve as a flexible replacement for glass in electronic displaydevices provided that they have suitable properties. These materials canfunction as a component of Liquid Crystal Displays (“LCDs”), where theirmodest consumption of electrical power, light weight, and layer flatnessare critical properties for effective utility. Other uses in electronicdisplay devices that place such parameters at a premium include devicesubstrates, substrates for color filter sheets, cover films, touchscreen panels, and others.

A number of these components are also important in the construction andoperation of organic electronic devices having an organic light emittingdiode (“OLED”). OLEDs are promising for many display applicationsbecause of their high power conversion efficiency and applicability to awide range of end-uses. They are increasingly being used in cell phones,tablet devices, handheld/laptop computers, and other commercialproducts. These applications call for displays with high informationcontent, full color, and fast video rate response time in addition tolow power consumption.

Polyimide films generally possess sufficient thermal stability, highglass transition temperature, and mechanical toughness to meritconsideration for such uses. Also, polyimides generally do not develophaze when subject to repeated flexing, so they are often preferred overother transparent substrates like polyethylene terephthalate (PET) andpolyethylene naphthalate (PEN) in flexible display applications.

The traditional amber color of polyimides, however, precludes their usein some display applications such as color filters and touch screenpanels since a premium is placed on optical transparency. Further,polyimides are generally stiff, highly aromatic materials; and thepolymer chains tend to orient in the plane of the film/coating as thefilm/coating is being formed. This leads to differences in refractiveindex in the parallel vs. perpendicular directions of the film(birefringence) which produces optical retardation that can negativelyimpact display performance. If polyimides are to find additionalapplications in the displays market, a solution is needed to maintaintheir desirable properties, while at the same time improving theiroptical transparency and reducing the amber color and birefringence thatleads to optical retardation.

There is thus a continuing need for low-color materials that aresuitable for use in electronic devices.

SUMMARY

There is provided a polyamic acid having a repeat unit of Formula I

where:

-   -   R^(a) represents one or more different tetracarboxylic acid        component residues; and    -   R^(b) represents one or more different aromatic diamine residues        or aromatic diisocyanate residues;        wherein 5-100 mol % of R^(a) has Formula II

where:

-   -   R¹ is selected from the group consisting of H, halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R² is selected from the group consisting of halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R³ and R⁴ are the same or different and are selected from the        group consisting of alkyl, fluoroalkyl, and silyl;    -   x and y are the same or different and are an integer from 0-2;        and

* indicates a point of attachment.

There is further provided a composition comprising (a) the polyamic acidhaving the repeat unit of Formula I and (b) at least one high-boiling,aprotic solvent.

There is further provided a polyimide whose repeat units have thestructure in Formula III

where R^(a) and R^(b) are as defined in Formula I.

There is further provided a polyimide film comprising the repeat unit ofFormula III.

There is further provided one or more methods for preparing a polyimidefilm wherein the polyimide film has the repeat unit of Formula II.

There is further provided a flexible replacement for glass in anelectronic device wherein the flexible replacement for glass is apolyimide film having the repeat unit of Formula II.

There is further provided an electronic device having at least one layercomprising a polyimide film having the repeat unit of Formula II.

There is further provided an organic electronic device, such as an OLED,wherein the organic electronic device contains a flexible replacementfor glass as disclosed herein.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes an illustration of one example of a polyimide film thatcan act as a flexible replacement for glass.

FIG. 2 includes an illustration of one example of an electronic devicethat includes a flexible replacement for glass.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DETAILED DESCRIPTION

There is provided a polyamic acid having a repeat unit of Formula I, asdescribed in detail below.

There is further provided a composition comprising (a) the polyamic acidhaving a repeat unit of Formula I and (b) at least one high-boiling,aprotic solvent.

There is further provided a polyimide whose repeat units have thestructure in Formula III, as described in detail below.

There is further provided one or more methods for preparing a polyimidefilm wherein the polyimide film has the repeat unit of Formula II.

There is further provided a flexible replacement for glass in anelectronic device wherein the flexible replacement for glass is apolyimide film having the repeat unit of Formula II.

There is further provided an electronic device having at least one layercomprising a polyimide film having the repeat unit of Formula II.

There is further provided an organic electronic device, such as an OLED,wherein the organic electronic device contains a flexible replacementfor glass as disclosed herein.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms, followed by the Polyamic Acid Having the RepeatUnit Structure of Formula I, the Polyimide Having the Repeat UnitStructure of Formula III, the Methods for Preparing the Polyimide Films,and the Electronic Device.

1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms aredefined or clarified.

As used in the “Definitions and Clarification of Terms”, R, R^(a),R^(b), R′, R″ and any other variables are generic designations and maybe the same as or different from those defined in the formulas.

The term “alignment layer” is intended to mean a layer of organicpolymer in a liquid-crystal device (LCD) that aligns the moleculesclosest to each plate as a result of its being rubbed onto the LCD glassin one preferential direction during the LCD manufacturing process.

As used herein, the term “alkyl” includes branched and straight-chainsaturated aliphatic hydrocarbon groups. Unless otherwise indicated, theterm is also intended to include cyclic groups. Examples of alkyl groupsinclude methyl, ethyl, propyl, isopropyl, isobutyl, secbutyl, tertbutyl,pentyl, isopentyl, neopentyl, cyclopentyl, hexyl, cyclohexyl, isohexyland the like. The term “alkyl” further includes both substituted andunsubstituted hydrocarbon groups. In some embodiments, the alkyl groupmay be mono-, di- and tri-substituted. One example of a substitutedalkyl group is trifluoromethyl. Other substituted alkyl groups areformed from one or more of the substituents described herein. In certainembodiments alkyl groups have 1 to 20 carbon atoms. In otherembodiments, the group has 1 to 6 carbon atoms. The term is intended toinclude heteroalkyl groups. Heteroalkyl groups may have from 1-20 carbonatoms.

The term “aprotic” refers to a class of solvents that lack an acidichydrogen atom and are therefore incapable of acting as hydrogen donors.Common aprotic solvents include alkanes, carbon tetrachloride (CCl4),benzene, dimethyl formamide (DMF), N-methyl-2-Pyrrolidone (NMP),dimethylacetamide (DMAc), and many others.

The term “aromatic compound” is intended to mean an organic compoundcomprising at least one unsaturated cyclic group having 4n+2 delocalizedpi electrons. The term is intended to encompass both aromatic compoundshaving only carbon and hydrogen atoms, and heteroaromatic compoundswherein one or more of the carbon atoms within the cyclic group has beenreplaced by another atom, such as nitrogen, oxygen, sulfur, or the like.

The term “aryl” or “aryl group” a moiety formed by removal of one ormore hydrogen (“H”) or deuterium (“D”) from an aromatic compound. Thearyl group may be a single ring (monocyclic) or have multiple rings(bicyclic, or more) fused together or linked covalenty. A “hydrocarbonaryl” has only carbon atoms in the aromatic ring(s). A “heteroaryl” hasone or more heteroatoms in at least one aromatic ring. In someembodiments, hydrocarbon aryl groups have 6 to 60 ring carbon atoms; insome embodiments, 6 to 30 ring carbon atoms. In some embodiments,heteroaryl groups have from 4-50 ring carbon atoms; in some embodiments,4-30 ring carbon atoms.

The term “alkoxy” is intended to mean the group —OR, where R is alkyl.

The term “aryloxy” is intended to mean the group —OR, where R is aryl.

The term “allyl” is intended to mean the group —CH₂—CH═CH₂.

The term “vinyl” is intended to mean the group —CH═CH₂.

Unless otherwise indicated, all groups can be substituted orunsubstituted. An optionally substituted group, such as, but not limitedto, alkyl or aryl, may be substituted with one or more substituentswhich may be the same or different. Suitable substituents include alkyl,aryl, nitro, cyano, —N(R′)(R′), halo, hydroxy, carboxy, alkenyl,alkynyl, cycloalkyl, heteroaryl, alkoxy, aryloxy, heteroaryloxy,alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, arylalkyl, silyl,siloxy, siloxane, thioalkoxy, —S(O)₂—, —C(═O)—N(R′)(R″),(R′)(R″)N-alkyl, (R′)(R″)N-alkoxyalkyl, (R′)(R″)N-alkylaryloxyalkyl,—S(O)s-aryl (where s=0-2) or —S(O)s-heteroaryl (where s=0-2). Each R′and R″ is independently an optionally substituted alkyl, cycloalkyl, oraryl group. R′ and R″, together with the nitrogen atom to which they arebound, can form a ring system in certain embodiments. Substituents mayalso be crosslinking groups.

The term “amine” is intended to mean a compound or functional group thatcontains a basic nitrogen atom with a lone pair. It refers to the group—NH₂ or —NR₂, where R is the same or different at each occurrence andcan be an alkyl group or an aryl group. The term “diamine” is intendedto mean a compound or functional group that contains two basic nitrogenatoms with associated lone pairs. The term “bent diamine” is intended tomean a diamine wherein the two basic nitrogen atoms and associated lonepairs are asymmetrically disposed about the center of symmetry of thecorresponding compound or functional group, e.g. m-phenylenediamine:

The term “b*” is intended to mean the b* axis in the CIELab Color Spacethat represents the yellow/blue opponent colors. Yellow is representedby positive b* values, and blue is represented by negative b* values.Measured b* values may be affected by solvent, particularly sincesolvent choice may affect color measured on materials exposed tohigh-temperature processing conditions. This may arise as the result ofinherent properties of the solvent and/or properties associated with lowlevels of impurities contained in various solvents. Particular solventsare often preselected to achieve desired b* values for a particularapplication.

The term “birefringence” is intended to mean the difference in therefractive index in different directions in a polymer film or coating.This term usually refers to the difference between the x- or y-axis(in-plane) and the z-axis (out-of-plane) refractive indices.

The term “charge transport,” when referring to a layer, material,member, or structure is intended to mean such layer, material, member,or structure facilitates migration of such charge through the thicknessof such layer, material, member, or structure with relative efficiencyand small loss of charge. Hole transport materials facilitate positivecharge; electron transport materials facilitate negative charge.Although light-emitting materials may also have some charge transportproperties, the term “charge transport layer, material, member, orstructure” is not intended to include a layer, material, member, orstructure whose primary function is light emission.

The term “compound” is intended to mean an electrically unchargedsubstance made up of molecules that further include atoms, wherein theatoms cannot be separated from their corresponding molecules by physicalmeans without breaking chemical bonds. The term is intended to includeoligomers and polymers.

The term “linear coefficient of thermal expansion (CTE or a)” isintended to mean the parameter that defines the amount which a materialexpands or contracts as a function of temperature. It is expressed asthe change in length per degree Celsius and is generally expressed inunits of μm/m/° C. or ppm/° C.

α=(ΔL/L₀)/ΔT

Measured CTE values disclosed herein are made via known methods duringthe first or second heating scan. The understanding of the relativeexpansion/contraction characteristics of materials can be an importantconsideration in the fabrication and/or reliability of electronicdevices.

The term “dopant” is intended to mean a material, within a layerincluding a host material, that changes the electronic characteristic(s)or the targeted wavelength(s) of radiation emission, reception, orfiltering of the layer compared to the electronic characteristic(s) orthe wavelength(s) of radiation emission, reception, or filtering of thelayer in the absence of such material.

The term “electroactive” as it refers to a layer or a material, isintended to indicate a layer or material which electronicallyfacilitates the operation of the device. Examples of electroactivematerials include, but are not limited to, materials which conduct,inject, transport, or block a charge, where the charge can be either anelectron or a hole, or materials which emit radiation or exhibit achange in concentration of electron-hole pairs when receiving radiation.Examples of inactive materials include, but are not limited to,planarization materials, insulating materials, and environmental barriermaterials.

The term “tensile elongation” or “tensile strain” is intended to meanthe percentage increase in length that occurs in a material before itbreaks under an applied tensile stress. It can be measured, for example,by ASTM Method D882.

The prefix “fluoro” is intended to indicate that one or more hydrogensin a group have been replaced with fluorine.

The term “glass transition temperature (or T_(g))” is intended to meanthe temperature at which a reversible change occurs in an amorphouspolymer or in amorphous regions of a semi crystalline polymer where thematerial changes suddenly from a hard, glassy, or brittle state to onethat is flexible or elastomeric. Microscopically, the glass transitionoccurs when normally-coiled, motionless polymer chains become free torotate and can move past each other. T_(g)'s may be measured usingdifferential scanning calorimetry (DSC), thermo-mechanical analysis(TMA), or dynamic-mechanical analysis (DMA), or other methods.

The prefix “hetero” indicates that one or more carbon atoms have beenreplaced with a different atom. In some embodiments, the heteroatom isO, N, S, or combinations thereof.

The term “high-boiling” is intended to indicate a boiling point greaterthan 130° C.

The term “host material” is intended to mean a material to which adopant is added. The host material may or may not have electroniccharacteristic(s) or the ability to emit, receive, or filter radiation.In some embodiments, the host material is present in higherconcentration.

The term “isothermal weight loss” is intended to mean a material'sproperty that is directly related to its thermal stability. It isgenerally measured at a constant temperature of interest viathermogravimetric analysis (TGA). Materials that have high thermalstability generally exhibit very low percentages of isothermal weightloss at the required use or processing temperature for the desiredperiod of time and can therefore be used in applications at thesetemperatures without significant loss of strength, outgassing, and/orchange in structure.

The term “liquid composition” is intended to mean a liquid medium inwhich a material is dissolved to form a solution, a liquid medium inwhich a material is dispersed to form a dispersion, or a liquid mediumin which a material is suspended to form a suspension or an emulsion.

The term “matrix” is intended to mean a foundation on which one or morelayers is deposited in the formation of, for example, an electronicdevice. Non-limiting examples include glass, silicon, and others.

The term “1% TGA Weight Loss” is intended to mean the temperature atwhich 1% of the original polymer weight is lost due to decomposition(excluding absorbed water).

The term “optical retardation (or R_(TH))” is intended to mean thedifference between the average in-plane refractive index and theout-of-plane refractive index (i.e., the birefringence), this differencethen being multiplied by the thickness of the film or coating. Opticalretardation is typically measured for a given frequency of light, andthe units are reported in nanometers. It can be measured by Metricon orAxoscan.

The term “organic electronic device” or sometimes “electronic device” isherein intended to mean a device including one or more organicsemiconductor layers or materials.

The term “particle content” is intended to mean the number or count ofinsoluble particles that is present in a solution. Measurements ofparticle content can be made on the solutions themselves or on finishedmaterials (pieces, films, etc.) prepared from those films. A variety ofoptical methods can be used to assess this property.

The term “photoactive” refers to a material or layer that emits lightwhen activated by an applied voltage (such as in a light emitting diodeor chemical cell), that emits light after the absorption of photons(such as in down-converting phosphor devices), or that responds toradiant energy and generates a signal with or without an applied biasvoltage (such as in a photodetector or a photovoltaic cell).

The term “polyamic acid solution” refers to a solution of a polymercontaining amic acid units that have the capability of intramolecularcyclization to form imide groups.

The term “polyimide” refers to condensation polymers resulting from thereaction of one or more bifunctional carboxylic acid components with oneor more primary diamines or diisocyanates. They contain the imidestructure —CO—NR—CO— as a linear or heterocyclic unit along the mainchain of the polymer backbone.

The term “satisfactory,” when regarding a materials property orcharacteristic, is intended to mean that the property or characteristicfulfills all requirements/demands for the material in-use. For example,an isothermal weight loss of less than 1% at 350° C. for 3 hours innitrogen can be viewed as a non-limiting example of a “satisfactory”property in the context of the polyimide films disclosed herein.

The term “soft-baking” is intended to mean a process commonly used inelectronics manufacture wherein spin-coated materials are heated todrive off solvents and solidify a film. Soft-baking is commonlyperformed on a hot plate or in exhausted oven at temperatures between90° C. and 110° C. as a preparation step for subsequent thermaltreatment of coated layers or films.

The term “substrate” refers to a base material that can be either rigidor flexible and may include one or more layers of one or more materials,which can include, but are not limited to, glass, polymer, metal orceramic materials or combinations thereof. The substrate may or may notinclude electronic components, circuits, or conductive members.

The term “siloxane” refers to the group R₃SiOR₂Si—, where R is the sameor different at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl. In some embodiments, one or more carbons in an R alkyl group arereplaced with Si.

The term “siloxy” refers to the group R₃SiO—, where R is the same ordifferent at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl.

The term “silyl” refers to the group R₃Si—, where R is the same ordifferent at each occurrence and is H, C1-20 alkyl, fluoroalkyl, oraryl. In some embodiments, one or more carbons in an R alkyl group arereplaced with Si.

The term “spin coating” is intended to mean a process used to deposituniform thin films onto flat substrates. Generally, a small amount ofcoating material is applied on the center of the substrate, which iseither spinning at low speed or not spinning at all. The substrate isthen rotated at specified speeds in order to spread the coating materialuniformly by centrifugal force.

The term “laser particle counter test” refers to a method used to assessthe particle content of polyamic acid and other polymeric solutionswhereby a representative sample of a test solution is spin coated onto a5″ silicon wafer and soft baked/dried. The film thus prepared isevaluated for particle content by any number of standard measurementtechniques. Such techniques include laser particle detection and othersknown in the art.

The term “tensile modulus” is intended to mean the measure of thestiffness of a solid material that defines the initial relationshipbetween the stress (force per unit area) and the strain (proportionaldeformation) in a material like a film. Commonly used units are gigapascals (GPa).

The term “tetracarboxylic acid component” is intended to mean any one ormore of the following: a tetracarboxylic acid, a tetracarboxylic acidmonoanhydride, a tetracarboxylic acid dianhydride, a tetracarboxylicacid monoester, and a tetracarboxylic acid diester.

The term “transmittance” refers to the percentage of light of a givenwavelength impinging on a film that passes through the film so as to bedetectable on the other side. Light transmittance measurements in thevisible region (380 nm to 800 nm) are particularly useful forcharacterizing film-color characteristics that are most important forunderstanding the properties-in-use of the polyimide films disclosedherein.

The term “yellowness index (or YI)” refers to the magnitude ofyellowness relative to a standard. A positive value of YI indicates thepresence, and magnitude, of a yellow color. Materials with a negative YIappear bluish. It should also be noted, particularly for polymerizationand/or curing processes run at high temperatures, that YI can be solventdependent. The magnitude of color introduced using DMAC as a solvent,for example, may be different than that introduced using NMP as asolvent. This may arise as the result of inherent properties of thesolvent and/or properties associated with low levels of impuritiescontained in various solvents. Particular solvents are often preselectedto achieve desired YI values for a particular application.

In a structure where a substituent bond passes through one or more ringsas shown below,

it is meant that the substituent R may be bonded at any availableposition on the one or more rings.

The phrase “adjacent to,” when used to refer to layers in a device, doesnot necessarily mean that one layer is immediately next to anotherlayer. On the other hand, the phrase “adjacent R groups,” is used torefer to R groups that are next to each other in a chemical formula(i.e., R groups that are on atoms joined by a bond). Exemplary adjacentR groups are shown below:

In this specification, unless explicitly stated otherwise or indicatedto the contrary by the context of usage, where an embodiment of thesubject matter hereof is stated or described as comprising, including,containing, having, being composed of or being constituted by or ofcertain features or elements, one or more features or elements inaddition to those explicitly stated or described may be present in theembodiment. An alternative embodiment of the disclosed subject matterhereof, is described as consisting essentially of certain features orelements, in which embodiment features or elements that would materiallyalter the principle of operation or the distinguishing characteristicsof the embodiment are not present therein. A further alternativeembodiment of the described subject matter hereof is described asconsisting of certain features or elements, in which embodiment, or ininsubstantial variations thereof, only the features or elementsspecifically stated or described are present.

Further, unless expressly stated to the contrary, “or” refers to aninclusive or and not to an exclusive or. For example, a condition A or Bis satisfied by any one of the following: A is true (or present) and Bis false (or not present), A is false (or not present) and B is true (orpresent), and both A and B are true (or present).

Also, use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Group numbers corresponding to columns within the Periodic Table of theelements use the “New Notation” convention as seen in the CRC Handbookof Chemistry and Physics, 81^(st) Edition (2000-2001).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety, unless a particular passageis cited. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductive memberarts.

2. Polyamic Acid Having the Repeat Unit Structure of Formula I

The polyamic acid described herein has a repeat unit structure ofFormula I

where:

-   -   R^(a) represents one or more different tetracarboxylic acid        component residues; and    -   R^(b) represents one or more different aromatic diamine residues        or aromatic diisocyanate residues;        wherein 5-100 mol % of R^(a) has Formula II

where:

-   -   R¹ is selected from the group consisting of H, halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R² is selected from the group consisting of halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R³ and R⁴ are the same or different and are selected from the        group consisting of alkyl, fluoroalkyl, and silyl;    -   x and y are the same or different and are an integer from 0-2;        and    -   * indicates a point of attachment.

In Formula I, R^(a) represents one or more different tetracarboxylicacid component residues. By “tetracarboxylic acid component residue”here it is meant the moiety bonded to the four carboxy groups in atetracarboxylic acid component. This is further illustrated below.

Tetracarboxylic acid component R^(a)

In some embodiments of Formula I, 100 mol % of R^(a) has Formula II, asshown above. In some embodiments, 5-95 mol % of R^(a) has Formula II; insome embodiments, 10-90 mol %; in some embodiments, 20-80 mol %; in someembodiments, 30-70 mol %; in some embodiments, 40-60 mol %.

In some embodiments, at least 50 mol % of R^(a) has Formula II.

In some embodiments of Formula II, R¹ is H.

In some embodiments of Formula II, R¹ is F.

In some embodiments of Formula II, R¹ is cyano.

In some embodiments of Formula II, R¹ is hydroxyl.

In some embodiments of Formula II, R¹ is a C₁₋₈ alkyl; in someembodiments, a C₁₋₃ alkyl.

In some embodiments of Formula II, R¹ is a C₁₋₈ alkoxy; in someembodiments, a C₁₋₃ alkoxy.

In some embodiments of Formula II, R¹ is a C₁₋₈ fluoroalkyl; in someembodiments, a C₁₋₃ fluoroalkyl.

In some embodiments of Formula II, R′ is a C₁₋₈ perfluoroalkyl; in someembodiments a C₁₋₃ perfluoroalkyl.

In some embodiments of Formula II, R¹ is a silyl group.

In some embodiments of Formula II, R¹ is a C₆₋₁₈ unsubstitutedhydrocarbon aryl. In some embodiments, the hydrocarbon aryl is selectedfrom the group consisting of phenyl, biphenyl, and naphthyl.

In some embodiments of Formula II, R′ is a C₆₋₁₈ substituted hydrocarbonaryl, where the substituent is selected from the group consisting of F,C, Br, cyano, hydroxyl, alkyl, alkoxy, and silyl.

In some embodiments of Formula II, R¹ is a C₃₋₂₀ unsubstitutedheteroaryl. In some embodiments, the heteroaryl is an N-heteroaryl orO-heteroaryl. In some embodiments, the heteroaryl is selected the groupconsisting of furanyl, pyrrolyl, pyranyl, pyridyl, and carbazolyl.

In some embodiments of Formula II, R¹ is a C₃₋₂₀ substituted heteroaryl,where the substituent is selected from the group consisting of F, Cl,Br, cyano, hydroxyl, alkyl, alkoxy, and silyl.

In some embodiments of Formula II, R¹ is an allyl group.

In some embodiments of Formula II, R¹ is a vinyl group.

In some embodiments of Formula II, R² is F.

In some embodiments of Formula II, R² is cyano.

In some embodiments of Formula II, R² is hydroxyl.

In some embodiments of Formula II, R² is a C₁₋₈ alkyl; in someembodiments, a C₁₋₃ alkyl.

In some embodiments of Formula II, R² is a C₁₋₈ alkoxy; in someembodiments, a C₁₋₃ alkoxy.

In some embodiments of Formula II, R² is a C₁₋₈ fluoroalkyl; in someembodiments, a C₁₋₃ fluoroalkyl.

In some embodiments of Formula II, R² is a C₁₋₈ perfluoroalkyl; in someembodiments, a C₁₋₃ perfluoroalkyl.

In some embodiments of Formula II, R² is a silyl group.

In some embodiments of Formula II, R² is a C₆₋₁₈ unsubstitutedhydrocarbon aryl.

In some embodiments of Formula II, R² is a C₆₋₁₈ substituted hydrocarbonaryl, where the substituent is selected from the group consisting of F,C, Br, cyano, hydroxyl, alkyl, alkoxy, and silyl.

In some embodiments of Formula II, R² is a C₃₋₂₀ unsubstitutedheteroaryl. In some embodiments, the heteroaryl is an N-heteroaryl orO-heteroaryl. In some embodiments, the heteroaryl is selected the groupconsisting of furanyl, pyrrolyl, pyranyl, pyridyl, and carbazolyl.

In some embodiments of Formula II, R² is a C₃₋₂₀ substituted heteroaryl,where the substituent is selected from the group consisting of F, Cl,Br, cyano, hydroxyl, alkyl, alkoxy, and silyl.

In some embodiments of Formula I, R² is an allyl group.

In some embodiments of Formula II, R² is a vinyl group.

In some embodiments of Formula II, R¹ is a C₁₋₃ alkyl and R² is a C₁₋₃alkyl.

In some embodiments of Formula II, R′ is a C₁₋₃ alkyl and R² is a C₁₋₃perfluoroalkyl.

In some embodiments of Formula II, R¹ is a C₁₋₃ perfluoroalkyl and R² isa C₁₋₃ perfluoroalkyl.

In some embodiments of Formula II, at least one of R¹ and R² is afluorinated group. The fluorinated group is one having at least one Fsubstituent.

In some embodiments, the fluorinated group is a fluoroalkyl; in someembodiments, a perfluoroalkyl.

In some embodiments, the fluorinated group is a fluorinated hydrocarbonaryl.

In some embodiments of Formula II, at least one of R¹ and R² is anunsubstituted or substituted hydrocarbon aryl, which may optionally besubstituted.

In some embodiments of Formula II, R¹ and R² may be joined together toform an unsubstituted or substituted cyclic group. The cyclic group isselected from the group consisting of a cycloalkyl group, a hydrocarbonaryl group, and a heteroaryl group.

In some embodiments of Formula II, R¹ and R² are joined together to forma cycloalkyl group having 5-20 ring carbons. The cycloalkyl may have asingle ring, or two or more rings fused together. In some embodiments,the cycloalkyl group has 5-12 ring carbons; in some embodiments, 5-8ring carbons.

In some embodiments of Formula II, R¹ and R² are joined together to forman unsubstituted cycloalkyl group.

In some embodiments of Formula II, R¹ and R² are joined together to forma substituted cycloalkyl group, where the substituent is selected fromthe group consisting of F, C, Br, cyano, hydroxyl, alkyl, alkoxy, andsilyl.

In some embodiments of Formula II, R¹ and R² are joined together to forma hydrocarbon aryl group having 5-20 ring carbons. The hydrocarbon arylgroup may have a single ring, or two or more rings fused together. Insome embodiments, the hydrocarbon aryl group has 5-18 ring carbons; insome embodiments, 5-12 ring carbons.

In some embodiments of Formula II, R¹ and R² are joined together to forman unsubstituted hydrocarbon aryl group.

In some embodiments of Formula II, R¹ and R² are joined together to forma substituted hydrocarbon aryl group, where the substituent is selectedfrom the group consisting of F, C, Br, cyano, hydroxyl, alkyl, alkoxy,and silyl.

In some embodiments of Formula II, R¹ and R² are joined together to forma heteroaryl group having 3-20 ring carbons. The heteroaryl group mayhave a single ring, or two or more rings fused together. In someembodiments, the heteroaryl group has 5-18 ring carbons; in someembodiments, 5-12 ring carbons.

In some embodiments of Formula II, R¹ and R² are joined together to forman unsubstituted heteroaryl group.

In some embodiments of Formula II, R¹ and R² are joined together to forma substituted heteroaryl group, where the substituent is selected fromthe group consisting of F, C, Br, cyano, hydroxyl, alkyl, alkoxy, andsilyl.

In some embodiments of Formula II, R¹ and R² are joined together to forma group selected from the group consisting of cyclohexyl,spirofluorenyl, and carbazolyl.

In some embodiments of Formula II, x=0.

In some embodiments of Formula II, x=1.

In some embodiments of Formula II, x=2.

In some embodiments of Formula II, x>0.

In some embodiments of Formula II, y=0.

In some embodiments of Formula II, y=1.

In some embodiments of Formula II, y=2.

In some embodiments of Formula II, y>0.

In some embodiments of Formula II, x=y=0.

In some embodiments of Formula II, x>0 and at least one R³ is a C₁₋₈alkyl; in some embodiments, a C₁₋₃ alkyl.

In some embodiments of Formula II, x>0 and at least one R³ is a C₁₋₈fluoroalkyl.

In some embodiments of Formula II, x>0 and at least one R³ is a C₁₋₈perfluoroalkyl; in some embodiments a C₁₋₃ perfluoroalkyl.

In some embodiments of Formula II, x>0 and at least one R³ is a C₃₋₁₂silyl.

All of the above-described embodiments for R³ in Formula II, applyequally to R⁴ in Formula II.

In some embodiments of Formula I, 5-100 mol % of R^(a) represents aresidue from a tetracarboxylic acid dianhydride having Formula II-A

where:

-   -   R¹ is selected from the group consisting of H, halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R² is selected from the group consisting of halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R³ and R⁴ are the same or different and are selected from the        group consisting of alkyl, fluoroalkyl, and silyl; and    -   x and y are the same or different and are an integer from 0-2.

All of the above-described embodiments for R¹, R², R³, R⁴, x, and y inFormula II, apply equally to R¹, R², R³, R⁴, x, and y in Formula II-A.

Compounds of Formula II-A in which R¹ is alkyl, fluoroalkyl, hydrocarbonaryl, or heteroaryl and R² is alkyl, fluoroalkyl, hydrocarbon aryl, orheteroaryl may be prepared in a three step process, as shown in theScheme below. The steps are as follows: 1) condensation of at least twoequivalents of 3,4-dimethylphenol with the appropriate ketone in thepresence of strong acid and optional co-solvent, 2) oxidation of theresulting 2,3,6,7-tetramethylxanthene to the corresponding tetraacid,and 3) dehydration of the tetraacid to the dianhydride compound.

In the above scheme, [O] represents an oxidant.

Compounds of Formula l-A may also be prepared in 3-steps from1,1′-oxybis(3,4-dimethylbenzene (DXE) as shown in the Scheme below by asimilar set of conditions as described above.

Alternatively, Compounds of Formula l-A may also be prepared in 5-stepsfrom DXE as shown in the Scheme below beginning with halogenation withN-bromo- or N-iodosuccinimide or with pyridinium bromide perbromide orbromine or iodine or iodine monochloride. Halogen-metal exchange of themonohalogenated DXE with an alkyllithium followed by addition of theappropriate ketone yields the carbinol that can then be cyclized withacid. The resulting tetramethylxanthene can then be converted asdescribed above to the dianhydride monomer.

Compounds of Formula l-A in which both R¹ and R² are cyano may beprepared as described in the Scheme below. Regioselectivediihalogenation of DXE followed by monosubstitution with one equivalentof malononitrile using sodium hydride or other strong base undertetrakis(triphenylphoshine)palladium(0) catalysis (as described for arelated system in Marks, T. J. J. Am. Chem. Soc. 2015, 137,12521-12538), gives the aryl-substituted propanedinitrile. Treatment ofthe aryl-substituted propanedinitrile with strong base under Pd(II)catalysis gives ring closure to the 2,3,6,7-tetramethylxanthene-9,9-dicarbonitrile. The methyl groups are then oxidized to thetetraacid with potassium permanganate or with MnO₂ andN-hydroxyphthalimide (as described in, for example, Sasson, Y. OrganicProc. Res. & Dev. 2010, 14, 701-704) or the Mn(OAc)₂/Co(OAc)₂ AMOCO-typeprocess (Gomes, J. F. P. Chem. Rev. 2013, 113, 7421-7469).Cyclodehydration of the tetraacid as described above would then affordthe desired cyano-substituted xanthene dianhydride.

Some of these compounds have been prepared previously by the methodsdisclosed in S. Trofimenko, U.S. Pat. No. 5,051,520 A (1991), Adv.Polyimide Sc. Techno., Proc. Int. Conf. Polyimides, (1993), 3-14, and S.Trofimenko and B. C. Auman, Macromolecules 1994, 27, 1136-1146. Themethods provided herein offer advantages over the previously reportedmethods in that the new methods avoid the need for handling hazardoushydrofluoric acid while delivering high purity products in good yields.

Some specific examples of compounds having Formula II-A include, but arenot limited to the compounds shown below.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents one ormore additional aromatic tetracarboxylic acid component residues; insome embodiments, 10-90 mol %; in some embodiments 20-80 mol %; in someembodiments, 30-70 mol %; in some embodiments, 40-60 mol %. In someembodiments, R^(e) represents one or more additional aromatictetracarboxylic acid dianhydride residues.

In some embodiments of Formula I, 50 mol % or less of R^(a) representsone or more additional aromatic tetracarboxylic acid component residues.In some embodiments of Formula I, 20-50 mol % of R^(a) represents one ormore additional aromatic tetracarboxylic acid component residues; insome embodiments, 30-45 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents asingle additional tetracarboxylic acid component residue.

In some embodiments of Formula I, 5-95 mol % of R^(e) represents twoadditional tetracarboxylic acid component residues.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents threeadditional tetracarboxylic acid residues.

Examples of suitable aromatic tetracarboxylic acid dianhydrides include,but are not limited to, pyromellitic dianhydride (PMDA),3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA),4,4′-oxydiphthalic anhydride (ODPA),4,4′-hexafluoroiso-propylidenebisphthalic dianhydride (6FDA),3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA),3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA),4,4′-bisphenol-A dianhydride (BPADA), hydroquinone diphthalic anhydride(HQDEA), ethylene glycol bis (trimellitic anhydride) (TMEG-100),4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronapthalene-1,2-dicarboyxlicanhydride (DTDA); 4,4′-bisphenol A dianhydride (BPADA); cyclobutane-1,2, 3, 4-tetracarboxylic dianhydride (CBDA); and the like andcombinations thereof. These aromatic dianhydrides may optionally besubstituted with groups that are known in the art including alkyl, aryl,nitro, cyano, —N(R′)(R′), halo, hydroxy, carboxy, alkenyl, alkynyl,cycloalkyl, heteroaryl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl,perfluoroalkyl, perfluoroalkoxy, arylalkyl, silyl, siloxy, siloxane,thioalkoxy, —S(O)₂—, —C(═O)—N(R′)(R″), (R′)(R″)N-alkyl,(R′)(R″)N-alkoxyalkyl, (R′)(R″)N-alkylaryloxyalkyl, —S(O)s-aryl (wheres=0-2) or —S(O)s-heteroaryl (where s=0-2). Each R′ and R″ isindependently an optionally substituted alkyl, cycloalkyl, or arylgroup. R′ and R″, together with the nitrogen atom to which they arebound, can form a ring system in certain embodiments. Substituents mayalso be crosslinking groups.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents one ormore residues from tetracarboxylic acid dianhydrides selected from thegroup consisting of PMDA, BPDA, 6FDA, BTDA, and CBDA; in someembodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a PMDAresidue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a BPDAresidue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a 6FDAresidue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a BTDAresidue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a CBDAresidue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a PMDAresidue and a BPDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a PMDAresidue and a 6FDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(e) represents a PMDAresidue and a BTDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a PMDAresidue and a CBDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a BPDAresidue and a 6FDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a BPDAresidue and a BTDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a 6FDAresidue and a BTDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(a) represents a 6FDAresidue and a CBDA residue; in some embodiments 20-50 mol %.

In some embodiments of Formula I, 5-95 mol % of R^(e) represents a BTDAresidue and a CBDA residue; in some embodiments 20-50 mol %.

In Formula I, R^(b) represents one or more different aromatic diamineresidues or aromatic diisocyanate residues. By “aromatic diamineresidue” here it is meant the moiety bonded to the two amino groups inan aromatic diamine. By “aromatic diisocyanate residue” here it is meantthe moiety bonded to the two isocyanate groups in an aromaticdiisocyanate. This is further illustrated below.

Diamine/Diisocyanate R^(b)

In some embodiments of Formula I, R^(b) represents a single aromaticdiamine residue or aromatic diisocyanate residue.

In some embodiments of Formula I, R^(b) represents two differentaromatic diamine residues or aromatic diisocyanate residues.

In some embodiments of Formula I, R^(b) represents three differentaromatic diamine residues or aromatic diisocyanate residues.

In some embodiments of Formula I, R^(b) represents at least one aromaticdiamine residue.

In some embodiments of Formula I, R^(b) has at least one substituentselected from the group consisting of halogen, CN, NO₂, alkyl,fluoroalkyl, and silyl.

In some embodiments of Formula I, R^(b) has at least one substituentselected from the group consisting of F and C₁₋₃ perfluoroalkyl.

In some embodiments of Formula, R^(b) represents at least one aromaticdiamine residue. In some embodiments, the aromatic diamine is selectedfrom the group consisting of p-phenylene diamine (PPD),2,2′-dimethyl-4,4′-diaminobiphenyl (m-tolidine),3,3′-dimethyl-4,4′-diaminobiphenyl (o-tolidine),3,3′-dihydroxy-4,4′-diaminobiphenyl (HAB),9,9′-bis(4-aminophenyl)fluorene (FDA), o-tolidine sulfone (TSN),2,3,5,6-tetramethyl-1,4-phenylenediamine (TMPD),2,4-diamino-1,3,5-trmethyl benzene (DAM), 3,3′,5,5′-tetramethylbenzidine(3355TMB), 2,2′-bis(trifluoromethyl) benzidine (22TFMB or TFMB),2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-methylenedianiline (MDA), 4,4′-[1,3-phenylenebis(1-methyl-ethylidene)]bisaniline(Bis-M), 4,4′-[1,4-phenylenebis(1-methyl-ethylidene)]bisaniline (Bis-P),4,4′-oxydianiline (4,4′-ODA), m-phenylene diamine (MPD),3,4′-oxydianiline (3,4′-ODA), 3,3′-diaminodiphenyl sulfone (3,3′-DDS),4,4′-diaminodiphenyl sulfone (4,4′-DDS), 4,4′-diaminodiphenyl sulfide(ASD), 2,2-bis[4-(4-amino-phenoxy)phenyl]sulfone (BAPS),2,2-bis[4-(3-aminophenoxy)-phenyl]sulfone (m-BAPS),1,4′-bis(4-aminophenoxy)benzene (TPE-Q), 1,3′-bis(4-aminophenoxy)benzene(TPE-R), 1,3′-bis(4-amino-phenoxy)benzene (APB-133),4,4′-bis(4-aminophenoxy)biphenyl (BAPB), 4,4′-diaminobenzanilide (DABA),methylene bis(anthranilic acid) (MBAA),1,3′-bis(4-aminophenoxy)-2,2-dimethylpropane (DANPG),1,5-bis(4-aminophenoxy)pentane (DASMG), 1,3-bis(4-aminophenoxy)propane(DA3MG), 2,2′-bis[4-(4-aminophenoxy phenyl)]hexafluoropropane (HFBAPP),2,2-bis(4-aminophenyl) hexafluoropropane (Bis-A-AF),2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (Bis-AP-AF),2,2-bis(3-amino-4-methylphenyl) hexafluoropropane (Bis-AT-AF),4,4′-bis(4-amino-2-trifluoromethyl phenoxy)biphenyl (6BFBAPB),3,3′5,5′-tetramethyl-4,4′-diamino diphenylmethane (TMMDA), and the likeand combinations thereof.

In some embodiments of Formula, R^(b) represents at least one aromaticdiamine residue, where the aromatic diamine is selected from the groupconsisting of PPD, FDA, 4,4′-ODA, 3,4′-ODA, TFMB, Bis-A-AF, Bis-AT-AF,and Bis-P.

In some embodiments of Formula I, moieties resulting from monoanhydridemonomers are present as end-capping groups.

In some embodiments, the monoanhydride monomers are selected from thegroup consisting of phthalic anhydrides and the like and derivativesthereof.

In some embodiments, the monoanhydrides are present at an amount up to 5mol % of the total tetracarboxylic acid composition.

In some embodiments of Formula I, moieties resulting from monoaminemonomers are present as end-capping groups.

In some embodiments, the monoamine monomers are selected from the groupconsisting of aniline and the like and derivatives thereof.

In some embodiments, the monoamines are present at an amount up to 5 mol% of the total amine composition.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 100,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 150,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a molecular weight (M_(W))greater than 200,000 based on gel permeation chromatography withpolystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 250,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) greater than 300,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 100,000 and 400,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 150,000 and 350,000 based on gel permeationchromatography with polystyrene standards.

In some embodiments, the polyamic acid has a weight average molecularweight (M_(W)) between 200,000 and 300,000 based on gel permeationchromatography with polystyrene standards.

Any of the above embodiments for the polyamic acid can be combined withone or more of the other embodiments, so long as they are not mutuallyexclusive. For example, the embodiment in which R¹ is a C₁₋₃ alkyl canbe combined with the embodiment in which R² is C6-18 unsubstitutedhydrocarbon aryl and the embodiment in which 10-90 mol % of R^(a)represents a PMDA residue. The skilled person would understand whichembodiments were mutually exclusive and would thus readily be able todetermine the combinations of embodiments that are contemplated by thepresent application.

Overall polyamic acid compositions can be designated via the notationcommonly used in the art. For example, a polyamic acid having atetracarboxylic acid component that is 100% ODPA, and a diaminecomponent that is 90 mol % Bis-P and 10 mol % TFMB, would be representedas:

ODPA//Bis-P/22TFMB 100//90/10.

There is also provided a liquid composition comprising (a) the polyamicacid having a repeat unit of Formula I, and (b) at least onehigh-boiling aprotic solvent. The liquid composition is also referred toherein as the “polyamic acid solution”.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 150° C. or higher.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 175° C. or higher.

In some embodiments, the high-boiling aprotic solvent has a boilingpoint of 200° C. or higher.

In some embodiments, the high-boiling aprotic solvent is a polarsolvent. In some embodiments, the solvent has a dielectric constantgreater than 20.

Some examples of high-boiling aprotic solvents include, but are notlimited to, N-methyl-2-pyrrolidone (NMP), dimethyl acetamide (DMAc),dimethyl sulfoxide (DMSO), dimethyl formamide (DMF),N-butylpyrrolidinone (NBP), N,N-diethylacetamide (DEAc),tetramethylurea, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone,dibutyl carbitol, butyl carbitol acetate, diethylene glycol monoethylether acetate, propylene glycol monomethyl ether acetate and the like,and combinations thereof.

In some embodiments of the liquid composition, the solvent is selectedfrom the group consisting of NMP, DMAc, and DMF.

In some embodiments of the liquid composition, the solvent is NMP.

In some embodiments of the liquid composition, the solvent is DMAc.

In some embodiments of the liquid composition, the solvent is DMF.

In some embodiments of the liquid composition, the solvent is NBP.

In some embodiments of the liquid composition, the solvent is DEAc.

In some embodiments of the liquid composition, the solvent istetramethylurea.

In some embodiments of the liquid composition, the solvent is1,3-dimethyl-2-imidazolidinone.

In some embodiments of the liquid composition, the solvent isγ-butyrolactone.

In some embodiments of the liquid composition, the solvent is dibutylcarbitol.

In some embodiments of the liquid composition, the solvent is butylcarbitol acetate.

In some embodiments of the liquid composition, the solvent is diethyleneglycol monoethyl ether acetate.

In some embodiments of the liquid composition, the solvent is propyleneglycol monoethyl ether acetate.

In some embodiments, more than one of the high-boiling aprotic solventsidentified above is used in the liquid composition.

In some embodiments, additional cosolvents are used in the liquidcomposition.

In some embodiments, the liquid composition is <1 weight % polyamic acidin >99 weight % high-boiling aprotic solvent(s). As used herein, theterm “solvent(s)” refers to one or more solvents.

In some embodiments, the liquid composition is 1-5 weight % polyamicacid in 95-99 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 5-10 weight % polyamicacid in 90-95 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 10-15 weight % polyamicacid in 85-90 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 15-20 weight % polyamicacid in 80-85 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 20-25 weight % polyamicacid in 75-80 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 25-30 weight % polyamicacid in 70-75 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 30-35 weight % polyamicacid in 65-70 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 35-40 weight % polyamicacid in 60-65 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 40-45 weight % polyamicacid in 55-60 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 45-50 weight % polyamicacid in 50-55 weight % high-boiling aprotic solvent(s).

In some embodiments, the liquid composition is 50 weight % polyamic acidin 50 weight % high-boiling aprotic solvent(s).

The polyamic acid solutions can optionally further contain any one of anumber of additives. Such additives can be: antioxidants, heatstabilizers, adhesion promoters, coupling agents (e.g. silanes),inorganic fillers or various reinforcing agents so long as they don'tadversely impact the desired polyimide properties.

The polyamic acid solutions can be prepared using a variety of availablemethods with respect to the introduction of the components (i.e., themonomers and solvents). Some methods of producing a polyamic acidsolution include:

-   -   (a) a method wherein the diamine components and dianhydride        components are preliminarily mixed together and then the mixture        is added in portions to a solvent while stirring.    -   (b) a method wherein a solvent is added to a stirring mixture of        diamine and dianhydride components. (contrary to (a) above)    -   (c) a method wherein diamines are exclusively dissolved in a        solvent and then dianhydrides are added thereto at such a ratio        as allowing to control the reaction rate.    -   (d) a method wherein the dianhydride components are exclusively        dissolved in a solvent and then amine components are added        thereto at such a ratio to allow control of the reaction rate.    -   (e) a method wherein the diamine components and the dianhydride        components are separately dissolved in solvents and then these        solutions are mixed in a reactor.    -   (f) a method wherein the polyamic acid with excessive amine        component and another polyamic acid with excessive dianhydride        component are preliminarily formed and then reacted with each        other in a reactor, particularly in such a way as to create a        non-random or block copolymer.    -   (g) a method wherein a specific portion of the amine components        and the dianhydride components are first reacted and then the        residual diamine components are reacted, or vice versa.    -   (h) a method wherein the components are added in part or in        whole in any order to either part or whole of the solvent, also        where part or all of any component can be added as a solution in        part or all of the solvent.    -   (i) a method of first reacting one of the dianhydride components        with one of the diamine components giving a first polyamic acid.        Then reacting the other dianhydride component with the other        amine component to give a second polyamic acid. Then combining        the polyamic acids in any one of a number of ways prior to film        formation.        Generally speaking, a polyamic acid solution can be obtained        from any one of the polyamic acid solution preparation methods        disclosed above.

The polyamic acid solution can then be filtered one or more times inorder to reduce the particle content. The polyimide film generated fromsuch a filtered solution can show a reduced number of defects andthereby lead to superior performance in the electronics applicationsdisclosed herein. An assessment of the filtration efficiency can be madeby the laser partile counter test wherein a representative sample of thepolyamic acid solution is cast onto a 5″ silicon wafer. After softbaking/drying, the film is evaluated for particle content by any numberof laser particle counting techniques on instruments that arecommercially available and known in the art.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 40 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a partile content of less than 30 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 20 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield a particle content of less than 10 particles as measured by thelaser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield particle content of between 2 particles and 8 particles asmeasured by the laser particle counter test.

In some embodiments, the polyamic acid solution is prepared and filteredto yield particle content of between 4 particles and 6 particles asmeasured by the laser particle counter test.

Exemplary preparations of polyamic acid solutions are given in theexamples.

3. Polyamide Having the Repeat Unit Structure of Formula III

There is provided a polyimide having a repeat unit structure of FormulaIII

-   -   R^(a) represents one or more different tetracarboxylic acid        component residues; and    -   R^(b) represents one or more different aromatic diamine residues        or aromatic diisocyanate residues;        wherein 5-100 mol % of R^(a) has Formula II

where:

-   -   R¹ is selected from the group consisting of H, halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R² is selected from the group consisting of halogen, cyano,        hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl,        silyl, hydrocarbon aryl, substituted hydrocarbon aryl,        heteroaryl, substituted heteroaryl, vinyl, and allyl;    -   R³ and R⁴ are the same or different and are selected from the        group consisting of alkyl, fluoroalkyl, and silyl;    -   x and y are the same or different and are an integer from 0-2;        and

* indicates a point of attachment.

All of the above-described embodiments for R^(a) and R^(b) in Formula Iapply equally to R^(a) and R^(b) in Formula II.

All of the above-described embodiments for R¹, R², R³, R⁴, x, and y inFormula II as applied to Formula I, apply equally to R¹, R², R³, R⁴, x,and y in Formula II as applied to Formula II.

Polyimides can be made from any suitable polyimide precursor such as apolyamic acid, a polyamic acid ester, a polyisoimide, and a polyamicacid salt.

There is also provided a polyimide film, wherein the polyimide has arepeat unit structure of Formula II, as described above.

Polyimide films can be made by coating a polyimide precursor onto asubstrate and subsequently imidizing. This can be accomplished by athermal conversion process or a chemical conversion process.

Further, if the polyimide is soluble in suitable coating solvents, itcan be provided as an already-imidized polymer dissolved in the suitablecoating solvent and coated as the polyimide.

In some embodiments of the polyimide film, the in-plane coefficient ofthermal expansion (CTE) is less than 45 ppm/° C. between 50° C. and 200°C.; in some embodiments, less than 30 ppm/C; in some embodiments, lessthan 20 ppm/° C.; in some embodiments, less than 15 ppm/° C.; in someembodiments, between 0 ppm/° C. and 15 ppm/° C.

In some embodiments of the polyimide film, the glass transitiontemperature (T_(g)) is greater than 250° C. for a polyimide film curedat a temperature above 300° C.; in some embodiments, greater than 300°C.; in some embodiments, greater than 350° C.

In some embodiments of the polyimide film, the 1% TGA weight losstemperature is greater than 350° C.; in some embodiments, greater than400° C.; in some embodiments, greater than 450° C.

In some embodiments of the polyimide film, the tensile modulus isbetween 1.5 GPa and 8.0 GPa; in some embodiments, between 1.5 GPa and5.0 GPa.

In some embodiments of the polyimide film, the elongation to break isgreater than 10%.

In some embodiments of the polyimide film, the optical retardation isless than 2000; in some embodiments, less than 1500; in someembodiments, less than 1000; in some embodiments, less than 500; in someembodiments, less than 300; in some embodiments less than 200.

In some embodiments of the polyimide film, the birefringence at 550 or633 nm is less than 0.15; in some embodiments, less than 0.10; in someembodiments, less than 0.05; in some embodiments, less than 0.010; insome embodiments, less than 0.005.

In some embodiments of the polyimide film, the haze is less than 1.0%;in some embodiments less than 0.5%; in some embodiments, less than 0.1%.

In some embodiments of the polyimide film, the b* is less than 10; insome embodiments, less than 7.5; in some embodiments, less than 5.0; insome embodiments, less than 3.0.

In some embodiments of the polyimide film, the YI is less than 12; insome embodiments, less than 10; in some embodiments, less than 5.

In some embodiments of the polyimide film, the transmittance at 400 nmis greater than 40%; in some embodiments, greater than 50%; in someembodiments, greater than 60%.

In some embodiments of the polyimide film, the transmittance at 430 nmis greater than 60%; in some embodiments, greater than 70%.

In some embodiments of the polyimide film, the transmittance at 450 nmis greater than 70%; in some embodiments, greater than 80%.

In some embodiments of the polyimide film, the transmittance at 550 nmis greater than 70%; in some embodiments, greater than 80%.

In some embodiments of the polyimide film, the transmittance at 750 nmis greater than 70%; in some embodiments, greater than 80%; in someembodiments, greater than 90%.

In some embodiments of the polyimide film, the Tg is greater than 300°C. for a polyimide film cured at a temperature above 300° C. and the CTEis less than 30 ppm/° C.; in some embodiments, the Tg is greater than350° C. and the CTE is less than 20 ppm/° C.

In some embodiments of the polyimide film, the Tg is greater than 300°C. for a polyimide film cured at a temperature above 300° C. and theoptical retardation is less than 400; in some embodiment, the Tg isgreater than 350° C. and the optical retardation is less than 300; insome embodiment, the Tg is greater than 350° C. and the opticalretardation is less than 200; in some embodiment, the Tg is greater than350° C. and the optical retardation is less than 100.

In some embodiments of the polyimide film, the Tg is greater than 300°C. for a polyimide film cured at a temperature above 300° C., theoptical retardation is less than 500 nm, and the b* is less than 7.5; insome embodiment, the Tg is greater than 350° C., the optical retardationis less than 250 nm, and the b* is less than 5.0.

Any of the above embodiments for the polyimide film can be combined withone or more of the other embodiments, so long as they are not mutuallyexclusive.

4. Methods for Preparing the Polyimide Films

Generally, polyimide films can be prepared from polyimide precursors bychemical or thermal conversion. In some embodiments, the films areprepared from the corresponding polyamic acid solutions by chemical orthermal conversion processes. The polyimide films disclosed herein,particularly when used as flexible replacements for glass in electronicdevices, are prepared by thermal conversion processes.

Generally, polyimide films can be prepared from the correspondingpolyamic acid solutions by chemical or thermal conversion processes. Thepolyimide films disclosed herein, particularly when used as flexiblereplacements for glass in electronic devices, are prepared by thermalconversion or modified-thermal conversion processes, versus chemicalconversion processes.

Chemical conversion processes are described in U.S. Pat. Nos. 5,166,308and 5,298,331 which are incorporated by reference in their entirety. Insuch processes, conversion chemicals are added to the polyamic acidsolutions. The conversion chemicals found to be useful in the presentinvention include, but are not limited to, (i) one or more dehydratingagents, such as, aliphatic acid anhydrides (acetic anhydride, etc.) andacid anhydrides; and (ii) one or more catalysts, such as, aliphatictertiary amines (triethylamine, etc.), tertiary amines (dimethylaniline,etc.) and heterocyclic tertiary amines (pyridine, picoline,isoquinoilne, etc.). The anhydride dehydrating material is typicallyused in a slight molar excess of the amount of amide acid groups presentin the polyamic acid solution. The amount of acetic anhydride used istypically about 2.0-3.0 moles per equivalent of the polyamic acid.Generally, a comparable amount of tertiary amine catalyst is used.

Thermal conversion processes may or may not employ conversion chemicals(i.e., catalysts) to convert a polyamic acid casting solution to apolyimide. If conversion chemicals are used, the process may beconsidered a modified-thermal conversion process. In both types ofthermal conversion processes, only heat energy is used to heat the filmto both dry the film of solvent and to perform the imidization reaction.Thermal conversion processes with or without conversion catalysts aregenerally used to prepare the polyimide films disclosed herein.

Specific method parameters are pre-selected considering that it is notjust the film composition that yields the properties of interest.Rather, the cure temperature and temperature-ramp profile also playimportant roles in the achievement of the most desirable properties forthe intended uses disclosed herein. The polyamic acids should beimidized at a temperature at, or higher than, the highest temperature ofany subsequent processing steps (e.g. deposition of inorganic or otherlayer(s) necessary to produce a functioning display), but at atemperature which is lower than the temperature at which significantthermal degradation/discoloration of the polyimide occurs. It shouldalso be noted that an inert atmosphere is generally preferred,particularly when higher processing temperatures are employed forimidization.

For the polyamic acids/polyimides disclosed herein, temperatures of 300°C. to 400° C. are typically employed when subsequent processingtemperatures in excess of 300° C. are required. Choosing the propercuring temperature allows a fully cured polyimide which achieves thebest balance of thermal and mechanical properties. Because of this veryhigh temperature, an inert atmosphere is required. Typically, oxygenlevels in the oven of <100 ppm should be employed. Very low oxygenlevels enable the highest curing temperatures to be used withoutsignificant degradation/discoloration of the polymer. Catalysts thataccelerate the imidization process are effective at achieving higherlevels of imidization at cure temperatures between about 200° C. and300° C. This approach may be optionally employed if the flexible deviceis prepared with upper cure temperatures that are below the T of thepolyimide.

The amount of time in each potential cure step is also an importantprocess consideration. Generally, the time used for thehighest-temperature curing should be kept to a minimum. For 320° C.cure, for example, cure time can be up to an hour or so under an inertatmosphere; but at higher cure temperatures, this time should beshortened to avoid thermal degradation. Generally speaking, highertemperature dictates shorter time. Those skilled in the art willrecognize the balance between temperature and time in order to optimizethe properties of the polyimide for a particular end use.

In some embodiments, the polyamic acid solution is converted into apolyimide film via a thermal conversion process.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is less than 50 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is less than 40 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is less than 30 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is less than 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is between 10 μm and 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is between 15 μm and 20 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is 18 μm.

In some embodiments of the thermal conversion process, the polyamic acidsolution is spin-coated onto the matrix such that the soft-bakedthickness of the resulting film is less than 10 μm.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft baked on a hot plate in proximity mode wherein nitrogengas is used to hold the spin-coated matrix just above the hot plate.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft baked on a hot plate in full-contact mode wherein thespin-coated matrix is in direct contact with the hot plate surface.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft baked on a hot plate using a combination of proximity andfull-contact modes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 80° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 90° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 100° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 110° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 120° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 130° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked using a hot plate set at 140° C.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of more than 10 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of less than 10 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of less than 8 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of less than 6 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of 4 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of less than 4 minutes.

In some embodiments of the thermal conversion process, the spin-coatedmatrix is soft-baked for a total time of less than 2 minutes.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 2 pre-selected temperaturesfor 2 pre-selected time intervals, the latter of which may be the sameor different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 3 pre-selected temperaturesfor 3 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 4 pre-selected temperaturesfor 4 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 5 pre-selected temperaturesfor 5 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 6 pre-selected temperaturesfor 6 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 7 pre-selected temperaturesfor 7 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process the soft-bakedspin-coated matrix is subsequently cured at 8 pre-selected temperaturesfor 8 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 9 pre-selected temperaturesfor 9 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the soft-bakedspin-coated matrix is subsequently cured at 10 pre-selected temperaturesfor 10 pre-selected time intervals, each of which of the latter of whichmay be the same or different.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 80° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 100° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 100° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 150° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 150° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 200° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 200° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 250° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 250° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 300° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 300° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 350° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 350° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 400° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 400° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is equal to 450° C.

In some embodiments of the thermal conversion process, the pre-selectedtemperature is greater than 450° C.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 2 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 5 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 10 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 15 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 20 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 25 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 30 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 35 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 40 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 45 minutes.

In some of the thermal conversion process, one or more of thepre-selected time intervals is 50 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 55 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is greater than 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 60 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 90 minutes.

In some embodiments of the thermal conversion process, one or more ofthe pre-selected time intervals is between 2 minutes and 120 minutes.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film comprises the following steps in order.spin-coating a polyamic acid solution comprising two or moretetracarboxylic acid components and one or more diamine components in ahigh-boiling, aprotic solvent onto a matrix; soft-baking the spin-coatedmatrix; treating the soft-baked spin-coated matrix at a plurality ofpre-selected temperatures for a plurality of pre-selected time intervalswhereby the polyimide film exhibits properties that are satisfactory foruse in electronics applications like those disclosed herein.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film consists of the following steps in orderspin-coating a polyamic acid solution comprising two or moretetracarboxylic acid components and one or more diamine components in ahigh-boiling, aprotic solvent onto a matrix; soft-baking the spin-coatedmatrix; treating the soft-baked spin-coated matrix at a plurality ofpre-selected temperatures for a plurality of pre-selected time intervalswhereby the polyimide film exhibits properties that are satisfactory foruse in electronics applications like those disclosed herein.

In some embodiments of the thermal conversion process, the method forpreparing a polyimide film consists essentially of the following stepsin order spin-coating a polyamic acid solution comprising two or moretetracarboxylic acid components and one or more diamine components in ahigh-boiling, aprotic solvent onto a matrix; soft-baking the spin-coatedmatrix; treating the soft-baked spin-coated matrix at a plurality ofpre-selected temperatures for a plurality of pre-selected time intervalswhereby the polyimide film exhibits properties that are satisfactory foruse in electronics applications like those disclosed herein.

Typically, the polyamic acid solutions/polyimides disclosed herein arecoated/cured onto a supporting glass substrate to facilitate theprocessing through the rest of the display making process. At some pointin the process as determined by the display maker, the polyimide coatingis removed from the supporting glass substrate by a mechanical or laserlift off process. These processes separate the polyimide as a film withthe deposited display layers from the glass and enable a flexibleformat.

Often, this polyimide film with deposition layers is then bonded to athicker, but still flexible, plastic film to provide support forsubsequent fabrication of the display.

There are also provided modified-thermal conversion processes whereinconversion catalysts generally cause imidization reactions to run atlower temperatures than would be possible in the absence of suchconversion catalysts.

In some embodiments, the polyamic acid solution is converted into apolyimide film via a modified-thermal conversion process.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts selectedfrom the group consisting of tertiary amines.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains conversion catalysts selectedfrom the group consisting of tributylamine, dimethylethanolamine,isoquinoline, 1,2-dimethylimidazole, N-methylimidazole,2-methylimidazole, 2-ethyl-4-imidazole, 3,5-dimethylpyridine,3,4-dimethylpyridine, 2,5-dimethylpyrdine, 5-methylbenzimidazole, andthe like.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 5 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 3 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 1 weight percent or less of thepolyamic acid solution.

In some embodiments of the modified-thermal conversion process, theconversion catalyst is present at 1 weight percent of the polyamic acidsolution.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains tributylamine as a conversioncatalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains dimethylethanolamine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains isoquinoline as a conversioncatalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 1,2-dimethylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 3,5-dimethylpyridine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 5-methylbenzimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains N-methylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2-methylimidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2-ethyl-4-imidazole as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 3,4-dimethylpyrdine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution further contains 2,5-dimethylpyrdine as aconversion catalyst.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 50 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 40 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 30 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is between 10 μm and 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is between 15 μm and 20 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is 18 μm.

In some embodiments of the modified-thermal conversion process, thepolyamic acid solution is spin-coated onto the matrix such that thesoft-baked thickness of the resulting film is less than 10 μm.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft baked on a hot plate in proximity modewherein nitrogen gas is used to hold the spin-coated matrix just abovethe hot plate.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft baked on a hot plate in full-contact modewherein the spin-coated matrix is in direct contact with the hot platesurface.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft baked on a hot plate using a combination ofproximity and full-contact modes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 80° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 90° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 100° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 110° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 120° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 130° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked using a hot plate set at 140° C.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of more than 10minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of less than 10minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of less than 8minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of less than 6minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of 4 minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of less than 4minutes.

In some embodiments of the modified-thermal conversion process, thespin-coated matrix is soft-baked for a total time of less than 2minutes.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 2 pre-selectedtemperatures for 2 pre-selected time intervals, the latter of which maybe the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 3 pre-selectedtemperatures for 3 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 4 pre-selectedtemperatures for 4 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 5 pre-selectedtemperatures for 5 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 6 pre-selectedtemperatures for 6 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 7 pre-selectedtemperatures for 7 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process thesoft-baked spin-coated matrix is subsequently cured at 8 pre-selectedtemperatures for 8 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 9 pre-selectedtemperatures for 9 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thesoft-baked spin-coated matrix is subsequently cured at 10 pre-selectedtemperatures for 10 pre-selected time intervals, each of which of thelatter of which may be the same or different.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 80° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 100° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 100° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 150° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 150° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 200° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 200° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 220° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 220° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 230° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 230° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 240° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 240° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 250° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 250° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is greater than 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is equal to 300° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 300° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 290° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 280° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 270° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 260° C.

In some embodiments of the modified-thermal conversion process, thepre-selected temperature is less than 250° C.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 2 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 5 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 10 minutes.

In some embodiments of the modified-conversion process, one or more ofthe pre-selected time intervals is 15 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 20 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 25 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 30 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 35 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 40 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 45 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 50 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 55 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is 60 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is greater than 60 minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 60minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 90minutes.

In some embodiments of the modified-thermal conversion process, one ormore of the pre-selected time intervals is between 2 minutes and 120minutes.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film comprises the following steps inorder spin-coating a polyamic acid solution comprising two or moretetracartoxylic acid components and one or more diamine components and aconversion chemical in a high-boiling, aprotic solvent onto a matrix;soft-baking the spin-coated matrix; treating the soft-baked spin-coatedmatrix at a plurality of pre-selected temperatures for a plurality ofpre-selected time intervals whereby the polyimide film exhibitsproperties that are satisfactory for use in electronics applicationslike those disclosed herein.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film consists of the following steps inorder spin-coating a polyamic acid solution comprising two or moretetracarboxylic acid components and one or more diamine components and aconversion chemical in a high-boiling, aprotic solvent onto a matrix;soft-baking the spin-coated matrix; treating the soft-baked spin-coatedmatrix at a plurality of pre-selected temperatures for a plurality ofpre-selected time intervals whereby the polyimide film exhibitsproperties that are satisfactory for use in electronics applicationslike those disclosed herein.

In some embodiments of the modified-thermal conversion process, themethod for preparing a polyimide film consists essentially of thefollowing steps in order spin-coating a polyamic acid solutioncomprising two or more tetracarboxylic acid components and one or morediamine components and a conversion chemical in a high-boiling, aproticsolvent onto a matrix; soft-baking the spin-coated matrix; treating thesoft-baked spin-coated matrix at a plurality of pre-selectedtemperatures for a plurality of pre-selected time intervals whereby thepolyimide film exhibits properties that are satisfactory for use inelectronics applications like those disclosed herein.

5. The Electronic Device

The polyimide films disclosed herein can be suitable for use in a numberof layers in electronic display devices such as OLED and LCD Displays.Nonlimiting examples of such layers include device substrates, touchpanels, substrates for color filter sheets, cover films, and others. Theparticular materials' properties requirements for each application areunique and may be addressed by appropriate composition(s) and processingcondition(s) for the polyimide films disclosed herein.

In some embodiments, the flexible replacement for glass in an electronicdevice is a polyimide film having the repeat unit of Formula II, asdescribed in detail above.

Organic electronic devices that may benefit from having one or morelayers including at least one compound as described herein include, butare not limited to, (1) devices that convert electrical energy intoradiation (e.g., a light-emitting diode, light emitting diode display,lighting device, luminaire, or diode laser), (2) devices that detectsignals through electronics processes (e.g., photodetectors,photoconductive cells, photoresistors, photoswitches, phototransistors,phototubes, IR detectors, biosensors), (3) devices that convertradiation into electrical energy, (e.g., a photovoltaic device or solarcell), (4) devices that convert light of one wavelength to light of alonger wavelength, (e.g., a down-converting phosphor device); and (5)devices that include one or more electronic components that include oneor more organic semi-conductor layers (e.g., a transistor or diode).Other uses for the compositions according to the present inventioninclude coating materials for memory storage devices, antistatic films,biosensors, electrochromic devices, solid electrolyte capacitors, energystorage devices such as a rechargeable battery, and electromagneticshielding applications.

One illustration of a polyimide film that can act as a flexiblereplacement for glass as described herein is shown in FIG. 1. Theflexible film 100 can have the properties as described in theembodiments of this disclosure. In some embodiments, the polyimide filmthat can act as a flexible replacement for glass is included in anelectronic device. FIG. 2 illustrates the case when the electronicdevice 200 is an organic electronic device. The device 200 has asubstrate 100, an anode layer 110 and a second electrical contact layer,a cathode layer 130, and a photoactive layer 120 between them.Additional layers may optionally be present. Adjacent to the anode maybe a hole injection layer (not shown), sometimes referred to as a bufferlayer. Adjacent to the hole injection layer may be a hole transportlayer (not shown), including hole transport material. Adjacent to thecathode may be an electron transport layer (not shown), including anelectron transport material. As an option, devices may use one or moreadditional hole injection or hole transport layers (not shown) next tothe anode 110 and/or one or more additional electron injection orelectron transport layers (not shown) next to the cathode 130. Layersbetween 110 and 130 are individually and collectively referred to as theorganic active layers. Additional layers that may or may not be presentinclude color filters, touch panels, and/or cover sheets. One or more ofthese layers, in addition to the substrate 100, may also be made fromthe polyimide films disclosed herein.

The different layers will be discussed further herein with reference toFIG. 2. However, the discussion applies to other configurations as well.

In some embodiments, the different layers have the following range ofthicknesses: substrate 100, 5-100 microns, anode 110, 500-5000 Å, insome embodiments, 1000-2000 Å; hole injection layer (not shown), 50-2000Å, in some embodiments, 200-1000 Å; hole transport layer (not shown),50-3000 Å, in some embodiments, 200-2000 Å; photoactive layer 120,10-2000 Å, in some embodiments, 100-1000 Å; electron transport layer(not shown), 50-2000 Å, in some embodiments, 100-1000 Å; cathode 130,200-10000 Å, in some embodiments, 300-5000 Å. The desired ratio of layerthicknesses will depend on the exact nature of the materials used.

In some embodiments, the organic electronic device (OLED) contains aflexible replacement for glass as disclosed herein.

In some embodiments, an organic electronic device includes a substrate,an anode, a cathode, and a photoactive layer therebetween, and furtherincludes one or more additional organic active layers. In someembodiments, the additional organic active layer is a hole transportlayer. In some embodiments, the additional organic active layer is anelectron transport layer. In some embodiments, the additional organiclayers are both hole transport and electron transport layers.

The anode 110 is an electrode that is particularly efficient forinjecting positive charge carriers. It can be made of, for examplematerials containing a metal, mixed metal, alloy, metal oxide ormixed-metal oxide, or it can be a conducting polymer, and mixturesthereof. Suitable metals include the Group 11 metals, the metals inGroups 4, 5, and 6, and the Group 8-10 transition metals. If the anodeis to be light-transmitting, mixed-metal oxides of Groups 12, 13 and 14metals, such as indium-tin-oxide, are generally used. The anode may alsoinclude an organic material such as polyaniline as described in“Flexible light-emitting diodes made from soluble conducting polymer,”Nature vol. 357, pp 477 479 (11 Jun. 1992). At least one of the anodeand cathode should be at least partially transparent to allow thegenerated light to be observed.

Optional hole injection layers can include hole injection materials. Theterm “hole injection layer” or “hole injection material” is intended tomean electrically conductive or semiconductive materials and may haveone or more functions in an organic electronic device, including but notlimited to, planarization of the underlying layer, charge transportand/or charge injection properties, scavenging of impurities such asoxygen or metal ions, and other aspects to facilitate or to improve theperformance of the organic electronic device. Hole injection materialsmay be polymers, oligomers, or small molecules, and may be in the formof solutions, dispersions, suspensions, emulsions, colloidal mixtures,or other compositions.

The hole injection layer can be formed with polymeric materials, such aspolyaniline (PANI) or polyethylenedioxythiophene (PEDOT), which areoften doped with protonic acids. The protonic acids can be, for example,poly(styrenesulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonicacid), and the like. The hole injection layer 120 can include chargetransfer compounds, and the like, such as copper phthalocyanine and thetetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ). In someembodiments, the hole injection layer 120 is made from a dispersion of aconducting polymer and a colloid-forming polymeric acid. Such materialshave been described in, for example, published U.S. patent applications2004-0102577, 2004-0127637, and 2005-0205860.

Other layers can include hole transport materials. Examples of holetransport materials for the hole transport layer have been summarizedfor example, in Kirk-Othmer Encyclopedia of Chemical Technology, FourthEdition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole transportingsmall molecules and polymers can be used. Commonly used holetransporting molecules include, but are not limited to:4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (TDATA);4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine (MTDATA);N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD); 4, 4′-bis(carbazol-9-yl)biphenyl (CBP);1,3-bis(carbazol-9-yl)benzene (mCP); 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC);N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD); tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA);α-phenyl-4-N,N-diphenylaminostyrene (TPS); p-(diethylamino)benzaldehydediphenylhydrazone (DEH); triphenylamine (TPA);bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP);1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline (PPR or DEASP); 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane(DCZB); N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine(TTB); N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB); andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers include, but are not limited to,polyvinylcarbazole, (phenylmethyl)polysilane, poly(dioxythiophenes),polyanilines, and polypyrroles. It is also possible to obtain holetransporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate. In some cases, triarylamine polymers are used, especiallytriarylamine-fluorene copolymers. In some cases, the polymers andcopolymers are crosslinkable. Examples of crosslinkable hole transportpolymers can be found in, for example, published US patent application2005-0184287 and published PCT application WO 2005/052027. In someembodiments, the hole transport layer is doped with a p-dopant, such astetrafluorotetracyanoquinodimethane andperylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride.

Depending upon the application of the device, the photoactive layer 120can be a light-emitting layer that is activated by an applied voltage(such as in a light-emitting diode or light-emitting electrochemicalcell), a layer of material that absorbs light and emits light having alonger wavelength (such as in a down-converting phosphor device), or alayer of material that responds to radiant energy and generates a signalwith or without an applied bias voltage (such as in a photodetector orphotovoltaic device).

In some embodiments, the photoactive layer includes a compoundcomprising an emissive compound having as a photoactive material. Insome embodiments, the photoactive layer further comprises a hostmaterial. Examples of host materials include, but are not limited to,chrysenes, phenanthrenes, triphenylenes, phenanthrolines, naphthalenes,anthracenes, quinolines, isoquinolines, quinoxalines, phenylpyridines,carbazoles, indolocarbazoles, furans, benzofurans, dibenzofurans,benzodifurans, and metal quinolinate complexes. In some embodiments, thehost materials are deuterated.

In some embodiments, the photoactive layer comprises (a) a dopantcapable of electroluminescence having an emission maximum between 380and 750 nm, (b) a first host compound, and (c) a second host compound.Suitable second host compounds are described above.

In some embodiments, the photoactive layer includes only (a) a dopantcapable of electroluminescence having an emission maximum between 380and 750 nm, (b) a first host compound, and (c) a second host compound,where additional materials that would materially alter the principle ofoperation or the distinguishing characteristics of the layer are notpresent.

In some embodiments, the first host is present in higher concentrationthan the second host, based on weight in the photoactive layer.

In some embodiments, the weight ratio of first host to second host inthe photoactive layer is in the range of 10:1 to 1:10. In someembodiments, the weight ratio is in the range of 6:1 to 1:6; in someembodiments, 5:1 to 1:2; in some embodiments, 3:1 to 1:1.

In some embodiments, the weight ratio of dopant to the total host is inthe range of 1:99 to 20:80; in some embodiments, 5:95 to 15:85.

In some embodiments, the photoactive layer comprises (a) a redlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

In some embodiments, the photoactive layer comprises (a) a greenlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

In some embodiments, the photoactive layer comprises (a) a yellowlight-emitting dopant, (b) a first host compound, and (c) a second hostcompound.

Optional layers can function both to facilitate electron transport, andalso serve as a confinement layer to prevent quenching of the exciton atlayer interfaces. Preferably, this layer promotes electron mobility andreduces exciton quenching.

In some embodiments, such layers include other electron transportmaterials. Examples of electron transport materials which can be used inthe optional electron transport layer, include metal chelated oxinoidcompounds, including metal quinolate derivatives such astris(8-hydroxyquinolato)aluminum (AIQ),bis(2-methyl-8-quinolinolato)(p-phenylphenolato) aluminum (BAq),tetrakis-(8-hydroxyquinolato)hafnium (HfQ) andtetrakis-(8-hydroxyquinolato)zirconium (ZrQ); and azole compounds suchas 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD),3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthrolines such as4,7-diphenyl-1,10-phenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); triazines;fullerenes; and mixtures thereof. In some embodiments, the electrontransport material is selected from the group consisting of metalquinolates and phenanthroline derivatives. In some embodiments, theelectron transport layer further includes an n-dopant. N-dopantmaterials are well known. The n-dopants include, but are not limited to,Group 1 and 2 metals; Group 1 and 2 metal salts, such as LiF, CsF, andCs₂CO₃; Group 1 and 2 metal organic compounds, such as Li quinolate; andmolecular n-dopants, such as leuco dyes, metal complexes, such asW₂(hpp)₄ where hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido-[1,2-a]-pyrimidineand cobaltocene, tetrathianaphthacene,bis(ethylenedithio)tetrathiafulvalene, heterocyclic radicals ordiradicals, and the dimers, oligomers, polymers, dispiro compounds andpolycycles of heterocyclic radical or diradicals.

An optional electron injection layer may be deposited over the electrontransport layer. Examples of electron injection materials include, butare not limited to, Li-containing organometallic compounds, LiF, Li₂O,Li quinolate, Cs-containing organometallic compounds, CsF, Cs₂O, andCs₂CO₃. This layer may react with the underlying electron transportlayer, the overlying cathode, or both. When an electron injection layeris present, the amount of material deposited is generally in the rangeof 1-100 Å, in some embodiments 1-10 Å.

The cathode 130 is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used.

It is known to have other layers in organic electronic devices. Forexample, there can be layers (not shown) between the anode 110 and holeinjection layer (not shown) to control the amount of positive chargeinjected and/or to provide band-gap matching of the layers, or tofunction as a protective layer. Layers that are known in the art can beused, such as copper phthalocyanine, silicon oxy-nitride, fluorocarbons,silanes, or an ultra-thin layer of a metal, such as Pt. Alternatively,some or all of anode layer 110, active layer 120, or cathode layer 130,can be surface-treated to increase charge carrier transport efficiency.The choice of materials for each of the component layers is preferablydetermined by balancing the positive and negative charges in the emitterlayer to provide a device with high electroluminescence efficiency.

It is understood that each functional layer can be made up of more thanone layer.

The device layers can generally be formed by any deposition technique,or combinations of techniques, including vapor deposition, liquiddeposition, and thermal transfer. Substrates such as glass, plastics,and metals can be used. Conventional vapor deposition techniques can beused, such as thermal evaporation, chemical vapor deposition, and thelike. The organic layers can be applied from solutions or dispersions insuitable solvents, using conventional coating or printing techniques,including but not limited to spin-coating, dip-coating, roll-to-rolltechniques, ink-jet printing, continuous nozzle printing,screen-printing, gravure printing and the like.

For liquid deposition methods, a suitable solvent for a particularcompound or related class of compounds can be readily determined by oneskilled in the art. For some applications, it is desirable that thecompounds be dissolved in non-aqueous solvents. Such non-aqueoussolvents can be relatively polar, such as C₁ to C₂ alcohols, ethers, andacid esters, or can be relatively non-polar such as C₁ to C₁₂ alkanes oraromatics such as toluene, xylenes, trifluorotoluene and the like. Othersuitable liquids for use in making the liquid composition, either as asolution or dispersion as described herein, including the new compounds,includes, but not limited to, chlorinated hydrocarbons (such asmethylene chloride, chloroform, chlorobenzene), aromatic hydrocarbons(such as substituted and non-substituted toluenes and xylenes),including triflurotoluene), polar solvents (such as tetrahydrofuran(THP), N-methyl pyrrolidone) esters (such as ethylacetate) alcohols(isopropanol), ketones (cyclopentatone) and mixtures thereof. Suitablesolvents for electroluminescent materials have been described in, forexample, published PCT application WO 2007/145979.

In some embodiments, the device is fabricated by liquid deposition ofthe hole injection layer, the hole transport layer, and the photoactivelayer, and by vapor deposition of the anode, the electron transportlayer, an electron injection layer and the cathode onto the flexiblesubstrate.

It is understood that the efficiency of devices can be improved byoptimizing the other layers in the device. For example, more efficientcathodes such as Ca, Ba or LiF can be used. Shaped substrates and novelhole transport materials that result in a reduction in operating voltageor increase quantum efficiency are also applicable. Additional layerscan also be added to tailor the energy levels of the various layers andfacilitate electroluminescence.

In some embodiments, the device has the following structure, in order.substrate, anode, hole injection layer, hole transport layer,photoactive layer, electron transport layer, electron injection layer,cathode.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described below. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting. All publications, patent applications, patents, andother references mentioned herein are incorporated by reference in theirentirety.

EXAMPLES Abbreviations

6FDA=4,4′-hexafluoroiso-propylidenebisphthalic dianhydrideBPDA=3,3′,4,4′-biphenyl tetracarboxylic dianhydrideDA3MG=1,3-bis(4-aminophenoxy)propane (DA3MG)FDA=9,9′-bis(4-aminophenyl)fluorenePMDA=pyromellitic dianhydrideTFMB=2,2′-bis(trifluoromethyl) benzidine

Synthesis Example 1

This example illustrates the preparation of a compound having Formulal-A, Compound 3.

Step 1: 2,3,6,7-tetramethyl-9,9-bis(trifluoromethyl)-9H-xanthene

A 3 L 4-neck round bottom flask equipped with mechanical stirrer,internal thermometer and nitrogen bubbler was charged with1,1,1,3,3,3-hexafluoropropan-2-one trihydrate (100 g, 454.4 mmol),3,4-dimethylphenol (222 g, 1818.6 mmol) and trifluoromethane sulfonicacid (200.5 mL, 2272.1 mmol) in toluene (400 mL) was heated to 110-120°C. After 60 h, reaction mixture was cooled to room temperature and thevolatiles were removed under reduced pressure. The residue was cooled 0°C., ethanol (500 mL) was added and the mixture was stirred for 1 h atroom temperature. The solid material collected by filtration and driedunder vacuum to get2,3,6,7-tetramethyl-9,9-bis(trifluoromethyl)-9H-xanthene (81 g, 48%) asan off white crystalline solid. mp: 212-214° C.; FT-IR: 1125.63 cm⁻¹(C—F): ¹H NMR (400 MHz, CDCl₃) δ: 7.55 (s, 2H), 6.94 (s, 2H), 2.28 (s,12H); ¹⁹F NMR (376 MHz, CDCl₃) δ: −66.17; GCMS: 374.2 [M]⁺; UPLC: 94.73%purity (4.71 minutes retention time (min RT)).

Step 2: 9,9-bis (trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylicacid

A 10 L 4-neck round bottom flask equipped with mechanical stirrer,condenser and internal thermometer was charged with2,3,6,7-tetramethyl-9,9-bis (trifluoromethyl)-9H-xanthene (100 g, 267.1mmol), pyridine (3500 mL), deionized water (1000 mL) and KMnO₄ (422.1 g,2671.5 mmol, in 5 equal portions) at 80-85° C. over a period of 4 h.After completion of KMnO₄ addition, deionized water was added (500 mL)and the mixture was heated at 85-92° C. After 16 h, the reaction mixturewas cooled to 60-65° C., filtered through a bed of Celite@, and the bedwas washed with hot water (3600 mL). The combined filtrate was distilledat 60-65° C. under vacuum to a volume of 500 mL of crude suspension. Anaqueous 15% NaOH solution (320 mL) was added to the suspension at roomtemperature followed by KMnO₄ (232.3 g, 1469.3 mmol) in one lot. Theresulting mixture was heated to 95-98° C. After 2 h, the reactionmixture was allowed to cool to 60-65° C., and excess of KMnO₄ wasquenched with isopropanol (320 mL). The reaction mixture was filteredthrough a bed of Celite® and the bed was washed with hot water (1600mL). The combined filtrate was cooled to 10-15° C. and the pH wasadjusted to ˜2 using concentrated sulfuric acid (120 mL) and stirred for30 minutes at 15-20° C. The resulting solid was filtered, the wet cakewas washed with water (300 mL) and dried under vacuum. The still moistcompound was treated with 3.6 N H₂SO₄ (1500 mL) at 80-85° C. After 2 h,the resulting suspension was cooled to room temperature, filtered andthe wet cake was washed with deionized water (1000 mL) to obtain a whitesolid, which was dried at 50-55° C. for 24 h to give 9,9-bis(trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylic acid (108.4 g, 82%) as awhite solid. ¹H NMR (400 MHz, DMSO-d₆) δ: 13.31 (bs, 4H), 8.30 (s, 2H),7.46 (s, 2H); MS: m/z=493.2 [M−H]⁺; LCMS: 95.42% purity (2.05 min RT).

Step 3: 11,11-bis(trifluoromethyl)-1H-difuro[3,4-b:3′,4′-i]xanthene-1,3,7,9(11H)-tetraone, Compound 3

A 3 L 4-neck round bottom flask equipped with mechanical stirrer,condenser, internal thermometer and nitrogen bubbler was charged with9,9-bis(trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylic acid (405g, 819.4 mmol) and acetic anhydride (1215 mL) at room temperature. Theresulting suspension was heated to 80-85° C. After 12 h, reactionmixture was cooled to room temperature, the solid material was collectedby filtration and dried under vacuum for 15 minutes. Toluene (810 mL)was added to the solid and stirred for 1 h at room temperature. Thesolid was collected by filtration and washed with toluene (405 mL), thendried at 50-55° C. under vacuum to give11,11-bis(trifluoromethyl)-1H-difuro[3,4-b:3′,4′-i]xanthene-1,3,7,9(11H)-tetraone (316 g, 82%) as a white solid.mp: 359-361° C.; FT-IR: 1783.90 cm⁻¹ (C═O); ¹H NMR (400 MHz, acetone-do)δ: 8.58 (t, 2H), 8.16 (s, 2H): ¹⁹F NMR (376 MHz, acetone-d₆) δ: −66.57;MS: m/z=458.0 [M]⁺; HPLC: 99.86% purity (4.44 min RT).

Compound 1, Compound 2, Compound 4, Compound 5, Compound 5, Compound 6,Compound 7, Compound 8, Compound 9, Compound 10, Compound 11, Compound12, Compound 15, Compound 16, Compound 17 and Compound 20 can beprepared using an analogous procedure. In the cases where highlyvolatile ketones were used (Compound 1 and Compound 2), a Hastelloyautoclave was used as the reaction vessel instead of a round bottomflask in Step 1.

Synthesis Example 2

This example illustrates the preparation of a compound having Formulal-A, Compound 18.

Step 1: 1-bromo-2-(3,4-dimethylphenoxy)-4,5-dimethylbenzene

A 20 L 4-neck round bottom flask equipped with mechanical stirrer, 2 Laddition funnel and internal thermometer was charged with4,4′-oxybis(1,2-dimethylbenzene) (150 g, 662 mmol) and dichloromethane(7.5 L). The resulting solution was cooled to −78° C. under argonatmosphere and bromine (34.1 mL, 662.7 mmol) in dichloromethane (1.5 L)was added drop wise over a period of 30 min. After 4 h, the reactionmixture was allowed to warm to room temperature. Excess bromine wasquenched with 10% aqueous sodium bisulfite solution (750 mL) and thesolution was extracted with dichloromethane. The organic layer waswashed with saturated sodium bicarbonate solution and brine, then driedover anhydrous sodium sulfate and concentrated under reduced pressure.The crude product was purified by washing with ethanol (450 mL) anddried under vacuum to get1-bromo-2-(3,4-dimethylphenoxy)-4,5-dimethylbenzene (160 g, 80%) as awhite solid. ¹H NMR (400 MHz, CDCl₃) δ: 7.36 (s, 1H), 7.05 (d, J=8 Hz,1H), 6.73 (s, 2H), 6.65 (dd, J=8.4, 2.8 Hz, 1H), 2.21 (s, 9H), 2.14 (s,3H); LCMS: 305.14 [M]⁺: HPLC: 88% purity (5.41 min RT).

Step 2: (2-(3,4-dimethylphenoxy)-4,5-dimethylphenyl)diphenylmethanol

A 3 L 4-neck round bottom flask equipped with magnetic stir bar, 1 Laddition funnel and internal thermometer was charged with1-bromo-2-(3,4-dimethylphenoxy)-4,5-dimethylbenzene (120 g, 394.7 mmol)and THF (1.0 L) under argon atmosphere. The resulting solution wascooled to −78° C. and 1.4 M sec-BuLi in hexane (422 mL, 592 mmol) wasadded dropwise over a period of 15 minutes. The reaction mixture wasstirred for 1 h and then benzophenone (71.8 g, 394.7 mmol) in THE (200mL) was added dropwise at −78° C. The reaction mixture was allowed towarm to room temperature and stirred for 16 h before quenching withsaturated aqueous ammonium chloride (200 mL) at 0-5° C. and extractingwith ethyl acetate. The organic layer was washed with brine, then driedover Na₂SO₄ and concentrated. The crude product product was washed withpetroleum ether to give(2-(3,4-dimethylphenoxy)-4,5-dimethylphenyl)diphenylmethanol (100 g,63%), as a white solid. ¹H NMR (400 MHz, CDCl₃) δ: 7.34-7.23 (m, 10H),6.95 (d, J=8 Hz, 1H), 6.50-6.43 (m, 3H), 6.37 (s, 1H), 5.06 (s, 1H),2.17 (s, 3H), 2.13 (s, 3H), 2.10 (s, 3H), 2.05 (s, 3H); GCMS: 408 [M]⁺;HPLC: 99.28% purity (5.4 min RT).

Step 3: 2,3,6,7-tetramethyl-9,9-diphenyl-9H-xanthene

A 3 L 4-neck round bottom flask equipped with mechanical stirrer, 1 Laddition funnel and internal thermometer was charged with(2-(3,4-dimethylphenoxy)-4,5-dimethylphenyl)diphenylmethanol (200 g,489.9 mmol) and dichloromethane (2 L). The resulting solution was cooledto 0-5° C. under argon atmosphere and BF₃.OEt₂ (181.4 mL, 1469.8 mmol)was added drop wise over a period of 15 minutes. The resulting reactionmixture was stirred at room temperature for 16 h then diluted with water(2 L) and extracted with dichloromethane (2 L). The organic layer wasseparated, washed with saturated aq. NaHCOs (1 L) solution, then driedover Na₂SO₄ and concentrated under reduced pressure. The crude productwas purified by recrystallization from petroleum ether to get2,3,6,7-tetramethyl-9,9-diphenyl-9H-xanthene (168.5 g, 88%) as a whitesolid. ¹H NMR (400 MHz, CDCl₃) δ: 7.25-7.19 (m, 6H), 7.02-7.0 (m, 4H),6.90 (s, 2H), 6.60 (s, 2H), 2.23 (s, 6H), 2.12 (s, 6H); LCMS: m/z=391.43[M+1]⁺; HPLC: 98.41% purity (5.75 min RT).

Step 4: 9,9-diphenyl-9H-xanthene-2,3,6,7-tetracarboxylic acid

A 20 L 4-neck round bottom flask equipped with mechanical stirrer,condenser and internal thermometer was charged with2,3,6,7-tetramethyl-9,9-diphenyl-9H-xanthene (180.0 g, 460.9 mmol),pyridine (6300 mL), deionized water (1800 mL) and potassium permanganate(400.5 g, 2535 mmol) at room temperature. The reaction mixture washeated to 95-100° C. for 16 h, then cooled to 60-65° C. and more KMnO₄(218 g, 1380 mmol) was added. The reaction mixture was heated to 95-100°C. After 24 h, reaction mixture was cooled to 60-65° C., then filteredthrough a bed of Celite® and the bed was washed with hot water (4320mL). The combined filtrate was distilled at 60-65° C. under vacuum to avolume of 1000 mL of crude suspension. 50% NaOH solution (576 mL),deionized water (1800 mL) and KMnO₄ (400.5 g, 2535 mmol) were added tothe suspension at room temperature. The resulting mixture was heated to95-100° C. After 16 h, reaction mixture was cooled to 60-65° C., andexcess of KMnO₄ was quenched with isopropanol (216 mL). The mixture wasfiltered through a bed of Celite@ and the bed was washed with hot water(2700 mL). The combined filtrate was cooled to 10-15° C. and the pH wasadjusted to 1-2 using conc. H₂SO₄ (360 mL) and stirred for 30 min at15-20° C. The resulting solid was collected by filtration, washed withwater (540 mL) and dried under vacuum. The solid was washed with EtOAc(1000 mL) and dried under vacuum, then treated with 3 N H₂SO₄ solution(2700 mL) at 70° C. After 1 h, the resulting suspension was cooled toroom temperature, filtered and the wet cake was washed with deionizedwater (720 mL) and dried under vacuum at room temperature for 24 h. Theresulting solid was dissolved in acetone (1.8 L) and filtered through abed of Celite® and the bed was washed with acetone (200 mL). Thecombined acetone layer was evaporated under reduced pressure to give asolid, which was again washed with water (720 mL) and dried under vacuumfor 36 h at room temperature to get9,9-diphenyl-9H-xanthene-2,3,6,7-tetracarboxylic acid (145 g, 62%) as awhite solid. ¹H NMR (400 MHz, DMSO-d₆) δ: 13.31 (bs, 4H), 7.40-7.31 (m,8H), 6.92 (d, J=8 Hz, 4H); LCMS: m/z=511.38 [M+H]⁺; HPLC: 99.55% purity(4.24 min RT).

Step 5:11,11-diphenyl-1H-difuro[3,4-b:3′,4′-i]xanthene-1,3,7,9(11H)-tetraone,Compound 18

A 2 L 4-neck round bottom flask equipped with mechanical stirrer,condenser and internal thermometer was charged with a9,9-diphenyl-9H-xanthene-2,3,6,7-tetracarboxylic acid (100.0 g, 195.9mmol), acetic anhydride (300 mL) at room temperature. The resultingsuspension was heated to 70-75° C. under argon atmosphere. After 16 h,reaction mixture was cooled to room temperature and the solid wascollected by filtration and dried under vacuum for 30 min. Hexane (2 L)was added to the solid and stirred for 2 h at room temperature. Thesolid was collected by filtration and dried under vacuum to give11,11-diphenyl-1H-difuro[3,4-b:3′,4′-i]xanthene-1,3,7,9(11H)-tetraone(66 g, 71%) as a white solid. mp: 312-316° C.; FT-IR: 1776.45 cm⁻¹(C═O); ¹H NMR (400 MHz, CDCl₃) δ: 7.85 (s, 2H), 7.63 (s, 2H) 7.37-7.32(m, 6H), 6.86-6.83 (m, 4H); MS: m/z=474.0 [M]⁺; HPLC: 99.91% purity(4.60 min RT).

Compound 13 and Compound 14 can be prepared using an analogousprocedure.

Synthesis Example 3

This example illustrates the preparation of a compound having Formulal-A, Compound 19.

Step 1: 2′,3′,6′,7′-tetramethylspiro[9H-fluorene-9,9′-[9H]xanthene]

A 1 L 2-neck round bottom flask was charged with 9H-fluoren-9-one (36.04g, 200 mmol), 4,4′-oxybis(1,2-dimethylbenzene) (63.92 g, 240 mmol) andmethanesulfonic acid (52 mL, 800 mmol). The reaction was heated at 145°C. under nitrogen atmosphere. After 18 hours, the reaction was cooled toroom temperature, and dichloromethane (550 mL) was added to thereaction. The organic layer was washed with water (2×250 mL), aq. sodiumcarbonate (1M, 250 mL) and brine (250 mL). The organic layer was driedwith MgSO4 at room temperature for 30 min with stirring. The volume ofthe solution was reduced to ˜200 mL and hexanes (100 mL) was added. Thesolution was passed through a short column packed with basic alumina (2cm×8 cm) and silica gel (8 cm×8 cm), eluting withdichloromethane:hexanes (1:1). The product-containing fractions, withlight blue luminance under UV light, were collected and the solvent wasconcentrated under reduced pressure. The crude product wasrecrystallized from dichloromethane/acetonitrile to provide2′,3′,6′,7′-tetramethyl-spiro[9H-fluorene-9,9′-[9H]xanthene] (36.5 g) asa white crystalline material. ¹H NMR (500 MHz, CD₂Cl₂) δ: 7.85 (d,J=10.0 Hz, 2H), 7.40 (t, J=7.5 Hz, 2H), 7.23 (t, J=7.5 Hz, 2H), 7.11 (d,J=10.0 Hz, 2H), 7.02 (s, 2H), 6.10 (s, 2H), 2.23 (2, 6H), 1.93 (s, 6H);HPLC: 98.22% purity.

Step 2: Spiro[9H-fluorene-9,9′-[9H]xanthene]-2′,3′,6′,7′-tetracarboxylicacid

A 1 L round bottom flask was charged with2′3′,6′,7′-tetramethylspiro[9H-fluorene-9,9′-[9H]xanthene] (12.0 g, 5.15mmol) in pyridine (168 mL) and water (126 mL). Next, potassiumpermanganate (32.3 g, 33.5 mmol) was added in one portion, and thereaction was heated at 120° C. external temperature. After 6 hours, thereaction was cooled, filtered through Celite (126 g), washing the Celitewith warm (50° C.) water (2×120 mL). The filtrate was concentrated underreduced pressure to a volume of 280 mL. The filtrate was placed into a 1L round bottom flask, treated with 50% aq. sodium hydroxide (40.2 mL)then potassium permanganate (32.0 g, 5.15 mmol) in one portion, andheated at 120° C. external temperature. After 16 hours, the reaction wascooled to room temperature. Excess potassium permanganate was quenchedwith isopropanol (48 mL). After stirring at r.t. for 10 minutes, themixture was filtered through Celite (126 g) washing with 50° C. water(630 mL). The filtrate was concentrated under reduced pressure to avolume of 385 mL. After cooling in an ice bath, conc. aq. sulfuric acid(27.1 mL) was added in portions over 17 minutes. The white precipitateformed was filtered using Whatman #54 90 mm dia. hardened filter paper,then washed with water (130 mL, 130 mL, then 120 mL) to givespiro[9H-fluorene-9,9′-[9H]xanthene]-2′,3′,6′,7′-tetracarboxylic acid(13.9 g 88%) as a white solid after drying under high vacuum for 48hours at room temperature in a glove box antechamber. ¹H NMR (500 MHz,DMSO) δ: 8.05 (d, J=5.0 Hz, 2H), 7.90-7.70 (m, 2H), 7.47 (t, J=7.5 Hz,2H), 7.27 (t, J=7.5 Hz, 2H), 7.15 (d, J=5.0 Hz, 2H), 7.0-6.8 (m, 2H);LCMS: 490.53 [M−H₂O]; HPLC: 95.4% purity (2.09 min RT).

Step 3:Spiro[11H-difuro[3,4-b:3′,4′-i]xanthene-11,9′-[9H]fluorene]-1,3,7,9-tetrone,Compound 19

A 500-mL round bottom flask was charged with spiro[9H-fluorene]-9,9′-[9Hxanthene]-2′,3′,6′,7′-tetracarboxylic acid (6.0 g, 11.8 mmol) andchloroform (123 mL). To this at room temperature was added thionylchloride (21.3 mL, 86.4 mmol). The reaction was heated at 82° C. undernitrogen atmosphere. After 10 hours, the reaction was filtered through afine porosity sintered glass funnel. The filtrate was concentrated underreduced pressure to provide a solid. The solid was dried at roomtemperature in a glove box antechamber for 23 hours then triturated with1,4-dioxane (60 mL) for 25 minutes at room temperature. The solid wasdried at room temperature in a glove box antechamber for 2.5 days togivespiro[11H-difuro[3,4-b:3′,4′-i]xanthene-11,9′-[9H]fluorene]-1,3,7,9-tetrone(3.14 g, 52%) as a white solid, containing 1,4-dioxane (7.7% by weight).¹H NMR (500 MHz, CD₂Cl₂) δ: 7.97 (d, J=5.0 Hz, 2H), 7.95 (s, 2H), 7.56(t, J=7.5 Hz, 2H), 7.33 (t, J=7.5 Hz, 2H), 7.16 (d, J=5.0 Hz, 2H), 7.12(s, 2H). HPLC: 99.09% purity (2.40 min RT).

Example 1

This example illustrates the preparation of polyamic acid PAA-7 havingFormula I, using Compound 2. The composition of PAA-7 was

BPDA/Compound 2/6FDA//TFMB 20/50/30//100 in NMP

Into a 500 mL reaction flask equipped with a nitrogen inlet and outlet,mechanical stirrer and thermocouple were charged 22.42 g of TFMB (0.07moles) and 250.31 g of 1-Methyl-2-Pyrrolidinone (NMP). The mixture wasagitated under nitrogen at room temperature for about 30 minutes.Afterwards, 4.12 g (0.014 moles) of BPDA was added slowly in portions tothe stirring solution of the diamine followed by 14.15 g (0.035 moles)of Compound 2 and 8.40 g (0.019 mol) of 6FDA in portions. The additionrate of the dianhydrides was controlled, to keep the maximum reactiontemperature <30° C. After completion of the dianhydride addition, andadditional 27.81 g of NMP were used to wash in any remaining dianhydridepowder from containers and the walls of the reaction flask. Theresulting mixture was stirred for 7 days. Separately, a 5% solution of6FDA in NMP was prepared and added in small amounts (ca. ˜3.1 g) overtime to increase the molecular weight of the polymer and viscosity ofthe polymer solution. Brookfield cone and plate viscometry was used tomonitor the solution viscosity by removing small samples from thereaction flask for testing. A total of 13.99 g of this finishingsolution was added (0.697 g, 0.00157 moles 6FDA). The reaction proceededovernight at room temperature under gentle agitation to allow forpolymer equilibration. Final viscosity of the polymer solution was11,600 cps at 25 C.

Additional polyamic acids were prepared using an analogous procedure.The polyamic acids (“PAA”) are summarized in Table 1 below.

TABLE 1 Polyamic acid compositions Dianhydride (mol %) Diamine (mol %)PAA Cmpd Cmpd BPDA 6FDA PMDA TFMB DA3MG FDA PAA-1 3 100 100 PAA-2 2 100100 PAA-3 3 50 30 20 100 PAA-4 2 50 10 40 100 PAA-5 2 55 35 10 100 PAA-62 50 20 30 95 5 PAA-7 2 50 20 30 100 PAA-8 2 50 20 30 50 50 PAA-9 2 4060 50 50 PAA-10 2 40 50 10 50 50 PAA-11 19 50 20 30 100 PAA-12 5 50 2030 100 Cmpd = compound having Formula II-A selected from Compound 1through Compound 24 shown above

Examples 3-6

These examples illustrate the preparation and properties of polyimidefilms having Formula III.

A portion of a PAA solution prepared above was pressure filtered througha Whatman PolyCap HD 0.45 μm absolute filter into a EFD Nordsendispensing syringe barrel. This syringe barrel was attached to an EFDNordsen dispensing unit to apply several ml of polymer solution onto,and spin coat, a 6″ silicon wafer. The spin speed was varied into orderto obtain the desired soft-baked thickness of about 18 μm. Soft-bakingwas accomplished after coating by placing the coated wafer onto a hotplate set at 110° C., first in proximity mode (nitrogen flow to holdwafer just off the surface of the hot plate) for 1 minute, followed bydirect contact with the hot plate surface for 3 minutes. The thicknessof the soft-baked film was measured on a Tencor profilometer by removingsections of the coating from the wafer and then measuring the differencebetween coated and uncoated areas of the wafer. The spin coatingconditions were varied as necessary to obtain the desired ˜15 μm uniformcoating across the wafer surface.

Once the spin coating conditions were determined, several wafers werecoated, soft-baked, and placed in a Tempress tube furnace. After dosingthe furnace, a nitrogen purge was applied and the furnace was ramped to100° C. at 2.5° C./min and held there for about 30 min to allow athorough purge with nitrogen. The temperature was ramped through stagesto a maximum temperature of 375° C. and held there for 60 min. Afterthis, the heating was stopped and the temperature allowed to returnslowly to ambient temperature (no external cooling). Afterward, thewafers were removed from the furnace and the coatings were removed fromthe wafers by scoring the coating around the edge of the wafer with aknife and then soaking the wafers in water for at least several hours tolift the coating off the wafer. The resulting polyimide films allowed todry and then subjected to various property measurements.

A Hunter Lab spectrophotometer was used to measure b* and yellow indexalong with % transmittance (% T) over the wavelength range 350 nm-780nm. Thermal measurements on films were made using a combination ofthermogravimetric analysis and thermomechanical analysis as appropriatefor the specific parameters reported herein. Mechanical properties weremeasured using equipment from Instron.

The film properties are given in Table 2.

TABLE 2 Film properties Ex. 3 Ex. 4 Ex. 5 Ex. 6 PAA 1 2 4 5 Thickness9.86 10.15 9.97 10.16 T_(g), ° C. 402 416 407 400 CTE 5.54 12.28 11.8027.40 0.5% TGA 451 441 454 456 loss Haze, % 0.31 0.15 0.31 0.28 R_(TH)722 715 914 468 b* 3.95 8.69 7.19 4.26 YI 6.90 14.51 11.89 7.35 PAA isthe polyamic acid from Example 1; thickness is the cured fim thicknessin μm; CTE is the second determination in the temperature range 50-250°C. in ppm/° C.; TGA loss is the temperature at which 0.5% weight islost, in ° C.; R_(TH) is the optical retardation at 550 nm; YI is theyellow index

It can be seen from the data in Table 2, that the polyimide films havehigh T_(g) and low CTE values.

Examples 7-9

These examples illustrate the preparation and properties of polyimidefilms having Formula III.

Polyimide films were made and tested as described in Examples 3-6. Thefilm properties are given below in Table 3.

TABLE 3 Film properties Ex. 7 Ex. 8 Ex. 9 PAA 8 9 10 Thickness 9.9210.12 10.31 T_(g), ° C. 419 405 402 CTE 45.18 55.66 50.55 0.5% TGA 449463 462 loss Haze, % 0.21 0.14 0.31 R_(TH) 67 48 53 b* 5.96 4.37 9.40 YI9.85 7.32 15.12 PAA is the polyamic acid from Example 1; thickness isthe cured fim thickness in μm; CTE is the second determination in thetemperature range 50-250° C. in ppm/° C.; TGA loss is the temperature atwhich 0.5% weight is lost, in ° C.; R_(TH) is the optical retardation at550 nm; YI is the yellow index

It can be seen from the data in Table 3, that the polyimide films havehigh T_(q) and low optical retardation values.

Examples 10-14

These examples illustrate the preparation and properties of polyimidefilms having Formula III.

Polyimide films were made and tested as described in Examples 3-6,except that in Example 14 the cure temperature of 375° C. was held for15 minutes, not 60. The film properties are given below in Table 4.

TABLE 4 Film properties Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 PAA 3 6 7 1112 Thickness 10.09 10.13 9.86 10.34 9.73 T_(g), ° C. 410 392 400 406 396CTE 35.01 45.98 42.26 45.80 49.87 0.5% TGA 451 441 427 485 448 lossHaze, 0.24 0.22 0.16 0.29 0.17 R_(TH) 233 104 105 83 107 b* 2.91 3.342.02 1.96 3.04 YI 5.20 5.72 3.62 3.93 5.45 PAA is the polyamic acid fromExample 1; thickness is the cured fim thickness in μm; CTE is the seconddetermination in the temperature range 50-250° C. in ppm/° C.; TGA lossis the temperature at which 0.5% weight is lost, in ° C.; R_(TH) is theoptical retardation at 550 nm; YI is the yellow index

It can be seen from the data in Table 4, that the polyimide films havehigh T_(g), low optical retardation, and low color.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofinvention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.The use of numerical values in the various ranges specified herein isstated as approximations as though the minimum and maximum values withinthe stated ranges were both being preceded by the word “about.” In thismanner, slight variations above and below the stated ranges can be usedto achieve substantially the same results as values within the ranges.Also, the disclosure of these ranges is intended as a continuous rangeincluding every value between the minimum and maximum average valuesincluding fractional values that can result when some of components ofone value are mixed with those of different value. Moreover, whenbroader and narrower ranges are disclosed, it is within thecontemplation of this invention to match a minimum value from one rangewith a maximum value from another range and vice versa.

What is claimed is:
 1. A liquid composition comprising (a) a polyamicacid having a repeat unit structure of Formula I

where: R^(a) represents one or more different tetracarboxylic acidcomponent residues; and R^(b) represents one or more different aromaticdiamine residues or aromatic diisocyanate residues; wherein 5-100 mol %of R^(a) has Formula II

where: R¹ is selected from the group consisting of H, halogen, cyano,hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl, silyl,hydrocarbon aryl, substituted hydrocarbon aryl, heteroaryl, substitutedheteroaryl, vinyl, and allyl; R² is selected from the group consistingof halogen, cyano, hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy,fluoroalkyl, silyl, hydrocarbon aryl, substituted hydrocarbon aryl,heteroaryl, substituted heteroaryl, vinyl, and allyl; R³ and R⁴ are thesame or different and are selected from the group consisting of alkyl,fluoroalkyl, and silyl; x and y are the same or different and are aninteger from 0-2; and * indicates a point of attachment; and (b) atleast one high-boiling aprotic solvent.
 2. The liquid compositionaccording to claim 1, wherein at least one of R¹ and R² is a fluorinatedgroup.
 3. The liquid composition according to claim 1, wherein at leastone of R¹ and R² is an unsubstituted or substituted hydrocarbon aryl. 4.The liquid composition according to claim 1, wherein R¹ and R² arejoined together to form an unsubstituted or substituted cyclic groupselected from the group consisting of a cycloalkyl group, a hydrocarbonaryl group, and a heteroaryl group.
 5. The liquid composition accordingto claim 1, wherein 40-60 mol % of R^(a) has Formula II.
 6. A polyimidehaving a repeat unit structure of Formula III

R^(a) represents one or more different tetracarboxylic acid componentresidues; and R^(b) represents one or more different aromatic diamineresidues or aromatic diisocyanate residues; wherein 5-100 mol % of R^(a)has Formula II

where: R¹ is selected from the group consisting of H, halogen, cyano,hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy, fluoroalkyl, silyl,hydrocarbon aryl, substituted hydrocarbon aryl, heteroaryl, substitutedheteroaryl, vinyl, and allyl; R² is selected from the group consistingof halogen, cyano, hydroxyl, alkyl, heteroalkyl, alkoxy, heteroalkoxy,fluoroalkyl, silyl, hydrocarbon aryl, substituted hydrocarbon aryl,heteroaryl, substituted heteroaryl, vinyl, and allyl; R³ and R⁴ are thesame or different and are selected from the group consisting of alkyl,fluoroalkyl, and silyl; x and y are the same or different and are aninteger from 0-2; and * indicates a point of attachment.
 7. Thepolyimide film according to claim 6, wherein the film has a Tg greaterthan 350° C. and a CTE less than 20 ppm/° C.
 8. The polyimide filmaccording to claim 6, wherein the film has a Tg greater than 350° C. andan optical retardation less than
 100. 9. The polyimide film according toclaim 6, wherein the film has a Tg greater than 350° C., an opticalretardation less than 250 nm, and a b* value less than 5.0.
 10. Anelectronic device wherein a polyimide film having a repeat unit ofFormula III, according to claim 6, is used in device components selectedfrom the group consisting of device substrates, substrates for colorfilter sheets, cover films, and touch screen panels.